diff --git a/cmd/protoc-gen-go/internal_gengo/reflect.go b/cmd/protoc-gen-go/internal_gengo/reflect.go
index 2126ee9..4cc1089 100644
--- a/cmd/protoc-gen-go/internal_gengo/reflect.go
+++ b/cmd/protoc-gen-go/internal_gengo/reflect.go
@@ -289,6 +289,14 @@
 					if oneof := field.OneofType(); oneof != nil {
 						g.P("OneofName: ", strconv.Quote(string(oneof.Name())), ",")
 					}
+					if field.IsPacked() {
+						g.P("IsPacked: ", prototypePackage.Ident("True"), ",")
+					} else {
+						g.P("IsPacked: ", prototypePackage.Ident("False"), ",")
+					}
+					if field.IsWeak() {
+						g.P("IsWeak: true,")
+					}
 					// NOTE: MessageType and EnumType are populated by init.
 					g.P("},")
 				}
@@ -326,6 +334,9 @@
 				}
 				g.P("ExtensionRanges: [][2]", protoreflectPackage.Ident("FieldNumber"), "{", strings.Join(ss, ","), "},")
 			}
+			if message.Desc.IsMapEntry() {
+				g.P("IsMapEntry: true,")
+			}
 			// NOTE: Messages, Enums, and Extensions are populated by init.
 			g.P("},")
 		}
diff --git a/cmd/protoc-gen-go/testdata/annotations/annotations.pb.go b/cmd/protoc-gen-go/testdata/annotations/annotations.pb.go
index 71b33e9..ef72ffd 100644
--- a/cmd/protoc-gen-go/testdata/annotations/annotations.pb.go
+++ b/cmd/protoc-gen-go/testdata/annotations/annotations.pb.go
@@ -198,6 +198,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "AnnotationsTestField",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/comments/comments.pb.go b/cmd/protoc-gen-go/testdata/comments/comments.pb.go
index 17d1200..ad1462b 100644
--- a/cmd/protoc-gen-go/testdata/comments/comments.pb.go
+++ b/cmd/protoc-gen-go/testdata/comments/comments.pb.go
@@ -458,6 +458,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "Field1A",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "Oneof1AField1",
@@ -466,6 +467,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "Oneof1AField1",
 				OneofName:   "Oneof1a",
+				IsPacked:    prototype.False,
 			},
 		},
 		Oneofs: []prototype.Oneof{
diff --git a/cmd/protoc-gen-go/testdata/comments/deprecated.pb.go b/cmd/protoc-gen-go/testdata/comments/deprecated.pb.go
index 86e7968..ae3d74b 100644
--- a/cmd/protoc-gen-go/testdata/comments/deprecated.pb.go
+++ b/cmd/protoc-gen-go/testdata/comments/deprecated.pb.go
@@ -184,6 +184,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "deprecatedField",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/extensions/base/base.pb.go b/cmd/protoc-gen-go/testdata/extensions/base/base.pb.go
index 602d373..6dfb1f6 100644
--- a/cmd/protoc-gen-go/testdata/extensions/base/base.pb.go
+++ b/cmd/protoc-gen-go/testdata/extensions/base/base.pb.go
@@ -206,6 +206,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "field",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{4, 10}, {16, 536870912}},
diff --git a/cmd/protoc-gen-go/testdata/extensions/ext/ext.pb.go b/cmd/protoc-gen-go/testdata/extensions/ext/ext.pb.go
index e0b3b5b..2a948e1 100644
--- a/cmd/protoc-gen-go/testdata/extensions/ext/ext.pb.go
+++ b/cmd/protoc-gen-go/testdata/extensions/ext/ext.pb.go
@@ -1131,6 +1131,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "data",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -1143,6 +1144,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "extensionGroup",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -1158,6 +1160,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "repeatedXGroup",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/extensions/extra/extra.pb.go b/cmd/protoc-gen-go/testdata/extensions/extra/extra.pb.go
index 9bcf01a..a01577f 100644
--- a/cmd/protoc-gen-go/testdata/extensions/extra/extra.pb.go
+++ b/cmd/protoc-gen-go/testdata/extensions/extra/extra.pb.go
@@ -128,6 +128,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "data",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/fieldnames/fieldnames.pb.go b/cmd/protoc-gen-go/testdata/fieldnames/fieldnames.pb.go
index 32866bb..fff2bd7 100644
--- a/cmd/protoc-gen-go/testdata/fieldnames/fieldnames.pb.go
+++ b/cmd/protoc-gen-go/testdata/fieldnames/fieldnames.pb.go
@@ -426,6 +426,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "fieldOne",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "FieldTwo",
@@ -433,6 +434,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "FieldTwo",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "fieldThree",
@@ -440,6 +442,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "fieldThree",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "field__four",
@@ -447,6 +450,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "fieldFour",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "descriptor",
@@ -454,6 +458,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "descriptor",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "marshal",
@@ -461,6 +466,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "marshal",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "unmarshal",
@@ -468,6 +474,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "unmarshal",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "proto_message",
@@ -475,6 +482,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "protoMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "CamelCase",
@@ -482,6 +490,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "CamelCase",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "CamelCase_",
@@ -489,6 +498,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "CamelCase",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "camel_case",
@@ -496,6 +506,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "camelCase",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "CamelCase__",
@@ -503,6 +514,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "CamelCase",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "get_name",
@@ -510,6 +522,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "getName",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "name",
@@ -517,6 +530,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "OneofConflictA",
@@ -525,6 +539,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "OneofConflictA",
 				OneofName:   "oneof_conflict_a",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_no_conflict",
@@ -533,6 +548,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "oneofNoConflict",
 				OneofName:   "oneof_conflict_b",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "OneofConflictB",
@@ -541,6 +557,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "OneofConflictB",
 				OneofName:   "oneof_conflict_b",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_message_conflict",
@@ -549,6 +566,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "oneofMessageConflict",
 				OneofName:   "oneof_conflict_c",
+				IsPacked:    prototype.False,
 			},
 		},
 		Oneofs: []prototype.Oneof{
diff --git a/cmd/protoc-gen-go/testdata/import_public/a.pb.go b/cmd/protoc-gen-go/testdata/import_public/a.pb.go
index e324cc2..5cb190b 100644
--- a/cmd/protoc-gen-go/testdata/import_public/a.pb.go
+++ b/cmd/protoc-gen-go/testdata/import_public/a.pb.go
@@ -196,6 +196,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "m",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "e",
@@ -203,6 +204,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "e",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "local",
@@ -210,6 +212,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "local",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/import_public/b.pb.go b/cmd/protoc-gen-go/testdata/import_public/b.pb.go
index 9b6589e..878425a 100644
--- a/cmd/protoc-gen-go/testdata/import_public/b.pb.go
+++ b/cmd/protoc-gen-go/testdata/import_public/b.pb.go
@@ -143,6 +143,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "m",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "e",
@@ -150,6 +151,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "e",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/import_public/sub/a.pb.go b/cmd/protoc-gen-go/testdata/import_public/sub/a.pb.go
index ec8b341..faefc5e 100644
--- a/cmd/protoc-gen-go/testdata/import_public/sub/a.pb.go
+++ b/cmd/protoc-gen-go/testdata/import_public/sub/a.pb.go
@@ -546,6 +546,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "m2",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "s",
@@ -554,6 +555,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "s",
 				Default:     protoreflect.ValueOf(string("default")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "b",
@@ -562,6 +564,7 @@
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "b",
 				Default:     protoreflect.ValueOf(("default")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "f",
@@ -570,6 +573,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "f",
 				Default:     protoreflect.ValueOf(float64(math.NaN())),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_int32",
@@ -578,6 +582,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "oneofInt32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_int64",
@@ -586,6 +591,7 @@
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "oneofInt64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 		},
 		Oneofs: []prototype.Oneof{
@@ -603,6 +609,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "submessageOneofInt32",
 				OneofName:   "submessage_oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "submessage_oneof_int64",
@@ -611,6 +618,7 @@
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "submessageOneofInt64",
 				OneofName:   "submessage_oneof_field",
+				IsPacked:    prototype.False,
 			},
 		},
 		Oneofs: []prototype.Oneof{
diff --git a/cmd/protoc-gen-go/testdata/imports/test_a_1/m1.pb.go b/cmd/protoc-gen-go/testdata/imports/test_a_1/m1.pb.go
index 50006a4..91da206 100644
--- a/cmd/protoc-gen-go/testdata/imports/test_a_1/m1.pb.go
+++ b/cmd/protoc-gen-go/testdata/imports/test_a_1/m1.pb.go
@@ -241,6 +241,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "m1",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/imports/test_import_a1m1.pb.go b/cmd/protoc-gen-go/testdata/imports/test_import_a1m1.pb.go
index 67f5a50..fcb6000 100644
--- a/cmd/protoc-gen-go/testdata/imports/test_import_a1m1.pb.go
+++ b/cmd/protoc-gen-go/testdata/imports/test_import_a1m1.pb.go
@@ -133,6 +133,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "f",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/imports/test_import_a1m2.pb.go b/cmd/protoc-gen-go/testdata/imports/test_import_a1m2.pb.go
index 070d020..20ec02c 100644
--- a/cmd/protoc-gen-go/testdata/imports/test_import_a1m2.pb.go
+++ b/cmd/protoc-gen-go/testdata/imports/test_import_a1m2.pb.go
@@ -133,6 +133,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "f",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/imports/test_import_all.pb.go b/cmd/protoc-gen-go/testdata/imports/test_import_all.pb.go
index f4265e2..1ddae96 100644
--- a/cmd/protoc-gen-go/testdata/imports/test_import_all.pb.go
+++ b/cmd/protoc-gen-go/testdata/imports/test_import_all.pb.go
@@ -184,6 +184,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "am1",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "am2",
@@ -191,6 +192,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "am2",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "bm1",
@@ -198,6 +200,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "bm1",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "bm2",
@@ -205,6 +208,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "bm2",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "fmt",
@@ -212,6 +216,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "fmt",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/nopackage/nopackage.pb.go b/cmd/protoc-gen-go/testdata/nopackage/nopackage.pb.go
index 4174d6d..6bfdcee 100644
--- a/cmd/protoc-gen-go/testdata/nopackage/nopackage.pb.go
+++ b/cmd/protoc-gen-go/testdata/nopackage/nopackage.pb.go
@@ -205,6 +205,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "stringField",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "enum_field",
@@ -213,6 +214,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "enumField",
 				Default:     protoreflect.ValueOf(string("ZERO")),
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/proto2/enum.pb.go b/cmd/protoc-gen-go/testdata/proto2/enum.pb.go
index 3ff891b..f5d0dd4 100644
--- a/cmd/protoc-gen-go/testdata/proto2/enum.pb.go
+++ b/cmd/protoc-gen-go/testdata/proto2/enum.pb.go
@@ -611,6 +611,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "defaultDuplicate1",
 				Default:     protoreflect.ValueOf(string("duplicate1")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_duplicate2",
@@ -619,6 +620,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "defaultDuplicate2",
 				Default:     protoreflect.ValueOf(string("duplicate2")),
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/proto2/fields.pb.go b/cmd/protoc-gen-go/testdata/proto2/fields.pb.go
index e296e51..0e51367 100644
--- a/cmd/protoc-gen-go/testdata/proto2/fields.pb.go
+++ b/cmd/protoc-gen-go/testdata/proto2/fields.pb.go
@@ -1673,6 +1673,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "optionalBool",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_enum",
@@ -1680,6 +1681,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "optionalEnum",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_int32",
@@ -1687,6 +1689,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "optionalInt32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sint32",
@@ -1694,6 +1697,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "optionalSint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_uint32",
@@ -1701,6 +1705,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "optionalUint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_int64",
@@ -1708,6 +1713,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "optionalInt64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sint64",
@@ -1715,6 +1721,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "optionalSint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_uint64",
@@ -1722,6 +1729,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "optionalUint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sfixed32",
@@ -1729,6 +1737,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "optionalSfixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_fixed32",
@@ -1736,6 +1745,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "optionalFixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_float",
@@ -1743,6 +1753,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "optionalFloat",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sfixed64",
@@ -1750,6 +1761,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "optionalSfixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_fixed64",
@@ -1757,6 +1769,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "optionalFixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_double",
@@ -1764,6 +1777,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "optionalDouble",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_string",
@@ -1771,6 +1785,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "optionalString",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_bytes",
@@ -1778,6 +1793,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "optionalBytes",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_Message",
@@ -1785,6 +1801,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "optionalMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optionalgroup",
@@ -1792,6 +1809,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.GroupKind,
 				JSONName:    "optionalgroup",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_bool",
@@ -1799,6 +1817,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "requiredBool",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_enum",
@@ -1806,6 +1825,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "requiredEnum",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_int32",
@@ -1813,6 +1833,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "requiredInt32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_sint32",
@@ -1820,6 +1841,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "requiredSint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_uint32",
@@ -1827,6 +1849,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "requiredUint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_int64",
@@ -1834,6 +1857,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "requiredInt64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_sint64",
@@ -1841,6 +1865,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "requiredSint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_uint64",
@@ -1848,6 +1873,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "requiredUint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_sfixed32",
@@ -1855,6 +1881,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "requiredSfixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_fixed32",
@@ -1862,6 +1889,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "requiredFixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_float",
@@ -1869,6 +1897,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "requiredFloat",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_sfixed64",
@@ -1876,6 +1905,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "requiredSfixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_fixed64",
@@ -1883,6 +1913,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "requiredFixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_double",
@@ -1890,6 +1921,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "requiredDouble",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_string",
@@ -1897,6 +1929,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "requiredString",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_bytes",
@@ -1904,6 +1937,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "requiredBytes",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "required_Message",
@@ -1911,6 +1945,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "requiredMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "requiredgroup",
@@ -1918,6 +1953,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.GroupKind,
 				JSONName:    "requiredgroup",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_bool",
@@ -1925,6 +1961,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "repeatedBool",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_enum",
@@ -1932,6 +1969,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "repeatedEnum",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_int32",
@@ -1939,6 +1977,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "repeatedInt32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_sint32",
@@ -1946,6 +1985,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "repeatedSint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_uint32",
@@ -1953,6 +1993,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "repeatedUint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_int64",
@@ -1960,6 +2001,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "repeatedInt64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_sint64",
@@ -1967,6 +2009,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "repeatedSint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_uint64",
@@ -1974,6 +2017,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "repeatedUint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_sfixed32",
@@ -1981,6 +2025,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "repeatedSfixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_fixed32",
@@ -1988,6 +2033,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "repeatedFixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_float",
@@ -1995,6 +2041,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "repeatedFloat",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_sfixed64",
@@ -2002,6 +2049,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "repeatedSfixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_fixed64",
@@ -2009,6 +2057,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "repeatedFixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_double",
@@ -2016,6 +2065,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "repeatedDouble",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_string",
@@ -2023,6 +2073,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "repeatedString",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_bytes",
@@ -2030,6 +2081,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "repeatedBytes",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_Message",
@@ -2037,6 +2089,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "repeatedMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeatedgroup",
@@ -2044,6 +2097,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.GroupKind,
 				JSONName:    "repeatedgroup",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_bool",
@@ -2052,6 +2106,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "defaultBool",
 				Default:     protoreflect.ValueOf(bool(true)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_enum",
@@ -2060,6 +2115,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "defaultEnum",
 				Default:     protoreflect.ValueOf(string("ONE")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_int32",
@@ -2068,6 +2124,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "defaultInt32",
 				Default:     protoreflect.ValueOf(int32(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_sint32",
@@ -2076,6 +2133,7 @@
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "defaultSint32",
 				Default:     protoreflect.ValueOf(int32(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_uint32",
@@ -2084,6 +2142,7 @@
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "defaultUint32",
 				Default:     protoreflect.ValueOf(uint32(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_int64",
@@ -2092,6 +2151,7 @@
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "defaultInt64",
 				Default:     protoreflect.ValueOf(int64(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_sint64",
@@ -2100,6 +2160,7 @@
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "defaultSint64",
 				Default:     protoreflect.ValueOf(int64(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_uint64",
@@ -2108,6 +2169,7 @@
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "defaultUint64",
 				Default:     protoreflect.ValueOf(uint64(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_sfixed32",
@@ -2116,6 +2178,7 @@
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "defaultSfixed32",
 				Default:     protoreflect.ValueOf(int32(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_fixed32",
@@ -2124,6 +2187,7 @@
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "defaultFixed32",
 				Default:     protoreflect.ValueOf(uint32(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_float",
@@ -2132,6 +2196,7 @@
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "defaultFloat",
 				Default:     protoreflect.ValueOf(float32(3.14)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_sfixed64",
@@ -2140,6 +2205,7 @@
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "defaultSfixed64",
 				Default:     protoreflect.ValueOf(int64(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_fixed64",
@@ -2148,6 +2214,7 @@
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "defaultFixed64",
 				Default:     protoreflect.ValueOf(uint64(1)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_double",
@@ -2156,6 +2223,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "defaultDouble",
 				Default:     protoreflect.ValueOf(float64(3.1415)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_string",
@@ -2164,6 +2232,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "defaultString",
 				Default:     protoreflect.ValueOf(string("hello,\"world!\"\n")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_bytes",
@@ -2172,6 +2241,7 @@
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "defaultBytes",
 				Default:     protoreflect.ValueOf(("hello,ޭ\xbe\xef")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_zero_string",
@@ -2180,6 +2250,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "defaultZeroString",
 				Default:     protoreflect.ValueOf(string("")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_zero_bytes",
@@ -2188,6 +2259,7 @@
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "defaultZeroBytes",
 				Default:     protoreflect.ValueOf(("")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_float_neginf",
@@ -2196,6 +2268,7 @@
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "defaultFloatNeginf",
 				Default:     protoreflect.ValueOf(float32(math.Inf(-1))),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_float_posinf",
@@ -2204,6 +2277,7 @@
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "defaultFloatPosinf",
 				Default:     protoreflect.ValueOf(float32(math.Inf(+1))),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_float_nan",
@@ -2212,6 +2286,7 @@
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "defaultFloatNan",
 				Default:     protoreflect.ValueOf(float32(math.NaN())),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_double_neginf",
@@ -2220,6 +2295,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "defaultDoubleNeginf",
 				Default:     protoreflect.ValueOf(float64(math.Inf(-1))),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_double_posinf",
@@ -2228,6 +2304,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "defaultDoublePosinf",
 				Default:     protoreflect.ValueOf(float64(math.Inf(+1))),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_double_nan",
@@ -2236,6 +2313,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "defaultDoubleNan",
 				Default:     protoreflect.ValueOf(float64(math.NaN())),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_int32_int64",
@@ -2243,6 +2321,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapInt32Int64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_string_message",
@@ -2250,6 +2329,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapStringMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_fixed64_enum",
@@ -2257,6 +2337,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapFixed64Enum",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_bool",
@@ -2265,6 +2346,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "oneofBool",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_enum",
@@ -2273,6 +2355,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "oneofEnum",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_int32",
@@ -2281,6 +2364,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "oneofInt32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_sint32",
@@ -2289,6 +2373,7 @@
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "oneofSint32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_uint32",
@@ -2297,6 +2382,7 @@
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "oneofUint32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_int64",
@@ -2305,6 +2391,7 @@
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "oneofInt64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_sint64",
@@ -2313,6 +2400,7 @@
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "oneofSint64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_uint64",
@@ -2321,6 +2409,7 @@
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "oneofUint64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_sfixed32",
@@ -2329,6 +2418,7 @@
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "oneofSfixed32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_fixed32",
@@ -2337,6 +2427,7 @@
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "oneofFixed32",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_float",
@@ -2345,6 +2436,7 @@
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "oneofFloat",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_sfixed64",
@@ -2353,6 +2445,7 @@
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "oneofSfixed64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_fixed64",
@@ -2361,6 +2454,7 @@
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "oneofFixed64",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_double",
@@ -2369,6 +2463,7 @@
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "oneofDouble",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_string",
@@ -2377,6 +2472,7 @@
 				Kind:        protoreflect.StringKind,
 				JSONName:    "oneofString",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_bytes",
@@ -2385,6 +2481,7 @@
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "oneofBytes",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_Message",
@@ -2393,6 +2490,7 @@
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "oneofMessage",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneofgroup",
@@ -2401,6 +2499,7 @@
 				Kind:        protoreflect.GroupKind,
 				JSONName:    "oneofgroup",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_largest_tag",
@@ -2409,6 +2508,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "oneofLargestTag",
 				OneofName:   "oneof_field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_two_1",
@@ -2417,6 +2517,7 @@
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "oneofTwo1",
 				OneofName:   "oneof_two",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_two_2",
@@ -2425,6 +2526,7 @@
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "oneofTwo2",
 				OneofName:   "oneof_two",
+				IsPacked:    prototype.False,
 			},
 		},
 		Oneofs: []prototype.Oneof{
@@ -2443,6 +2545,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "optionalGroup",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -2455,6 +2558,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "requiredGroup",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -2467,6 +2571,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "repeatedGroup",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -2479,6 +2584,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -2486,8 +2592,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "MapStringMessageEntry",
@@ -2498,6 +2606,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -2505,8 +2614,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "MapFixed64EnumEntry",
@@ -2517,6 +2628,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -2524,8 +2636,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "OneofGroup",
@@ -2536,6 +2650,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "oneofGroupField",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/proto2/nested_messages.pb.go b/cmd/protoc-gen-go/testdata/proto2/nested_messages.pb.go
index 19061d3..e47c90f 100644
--- a/cmd/protoc-gen-go/testdata/proto2/nested_messages.pb.go
+++ b/cmd/protoc-gen-go/testdata/proto2/nested_messages.pb.go
@@ -263,6 +263,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "l2",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "l3",
@@ -270,6 +271,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "l3",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -282,6 +284,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "l3",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/proto2/proto2.pb.go b/cmd/protoc-gen-go/testdata/proto2/proto2.pb.go
index db64579..7630e86 100644
--- a/cmd/protoc-gen-go/testdata/proto2/proto2.pb.go
+++ b/cmd/protoc-gen-go/testdata/proto2/proto2.pb.go
@@ -137,6 +137,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "i32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "m",
@@ -144,6 +145,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "m",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/cmd/protoc-gen-go/testdata/proto3/fields.pb.go b/cmd/protoc-gen-go/testdata/proto3/fields.pb.go
index 293a5b3..1701832 100644
--- a/cmd/protoc-gen-go/testdata/proto3/fields.pb.go
+++ b/cmd/protoc-gen-go/testdata/proto3/fields.pb.go
@@ -582,6 +582,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "optionalBool",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_enum",
@@ -589,6 +590,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "optionalEnum",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_int32",
@@ -596,6 +598,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "optionalInt32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sint32",
@@ -603,6 +606,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "optionalSint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_uint32",
@@ -610,6 +614,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "optionalUint32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_int64",
@@ -617,6 +622,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "optionalInt64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sint64",
@@ -624,6 +630,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "optionalSint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_uint64",
@@ -631,6 +638,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "optionalUint64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sfixed32",
@@ -638,6 +646,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "optionalSfixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_fixed32",
@@ -645,6 +654,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "optionalFixed32",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_float",
@@ -652,6 +662,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "optionalFloat",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_sfixed64",
@@ -659,6 +670,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "optionalSfixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_fixed64",
@@ -666,6 +678,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "optionalFixed64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_double",
@@ -673,6 +686,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "optionalDouble",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_string",
@@ -680,6 +694,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "optionalString",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_bytes",
@@ -687,6 +702,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "optionalBytes",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optional_Message",
@@ -694,6 +710,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "optionalMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_bool",
@@ -701,6 +718,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "repeatedBool",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_enum",
@@ -708,6 +726,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "repeatedEnum",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_int32",
@@ -715,6 +734,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "repeatedInt32",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_sint32",
@@ -722,6 +742,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sint32Kind,
 				JSONName:    "repeatedSint32",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_uint32",
@@ -729,6 +750,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Uint32Kind,
 				JSONName:    "repeatedUint32",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_int64",
@@ -736,6 +758,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "repeatedInt64",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_sint64",
@@ -743,6 +766,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sint64Kind,
 				JSONName:    "repeatedSint64",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_uint64",
@@ -750,6 +774,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "repeatedUint64",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_sfixed32",
@@ -757,6 +782,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sfixed32Kind,
 				JSONName:    "repeatedSfixed32",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_fixed32",
@@ -764,6 +790,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Fixed32Kind,
 				JSONName:    "repeatedFixed32",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_float",
@@ -771,6 +798,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.FloatKind,
 				JSONName:    "repeatedFloat",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_sfixed64",
@@ -778,6 +806,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Sfixed64Kind,
 				JSONName:    "repeatedSfixed64",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_fixed64",
@@ -785,6 +814,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "repeatedFixed64",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_double",
@@ -792,6 +822,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "repeatedDouble",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "repeated_string",
@@ -799,6 +830,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "repeatedString",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_bytes",
@@ -806,6 +838,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "repeatedBytes",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "repeated_Message",
@@ -813,6 +846,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "repeatedMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_int32_int64",
@@ -820,6 +854,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapInt32Int64",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_string_message",
@@ -827,6 +862,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapStringMessage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_fixed64_enum",
@@ -834,6 +870,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "mapFixed64Enum",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -846,6 +883,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -853,8 +891,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "MapStringMessageEntry",
@@ -865,6 +905,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -872,8 +913,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "MapFixed64EnumEntry",
@@ -884,6 +927,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Fixed64Kind,
 				JSONName:    "key",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -891,8 +935,10 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 		},
+		IsMapEntry: true,
 	},
 	{
 		Name: "Message",
diff --git a/internal/encoding/pack/pack_test.go b/internal/encoding/pack/pack_test.go
index 3a56ebb..73c2acb 100644
--- a/internal/encoding/pack/pack_test.go
+++ b/internal/encoding/pack/pack_test.go
@@ -14,8 +14,6 @@
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
 	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 	cmp "github.com/google/go-cmp/cmp"
-
-	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )
 
 var msgDesc = func() pref.MessageDescriptor {
@@ -23,16 +21,16 @@
 		Syntax:   pref.Proto2,
 		FullName: "Message",
 		Fields: []ptype.Field{
-			{Name: "F1", Number: 1, Cardinality: pref.Repeated, Kind: pref.BoolKind, Options: packedOpt(true)},
-			{Name: "F2", Number: 2, Cardinality: pref.Repeated, Kind: pref.Int64Kind, Options: packedOpt(true)},
-			{Name: "F3", Number: 3, Cardinality: pref.Repeated, Kind: pref.Sint64Kind, Options: packedOpt(true)},
-			{Name: "F4", Number: 4, Cardinality: pref.Repeated, Kind: pref.Uint64Kind, Options: packedOpt(true)},
-			{Name: "F5", Number: 5, Cardinality: pref.Repeated, Kind: pref.Fixed32Kind, Options: packedOpt(true)},
-			{Name: "F6", Number: 6, Cardinality: pref.Repeated, Kind: pref.Sfixed32Kind, Options: packedOpt(true)},
-			{Name: "F7", Number: 7, Cardinality: pref.Repeated, Kind: pref.FloatKind, Options: packedOpt(true)},
-			{Name: "F8", Number: 8, Cardinality: pref.Repeated, Kind: pref.Fixed64Kind, Options: packedOpt(true)},
-			{Name: "F9", Number: 9, Cardinality: pref.Repeated, Kind: pref.Sfixed64Kind, Options: packedOpt(true)},
-			{Name: "F10", Number: 10, Cardinality: pref.Repeated, Kind: pref.DoubleKind, Options: packedOpt(true)},
+			{Name: "F1", Number: 1, Cardinality: pref.Repeated, Kind: pref.BoolKind, IsPacked: ptype.True},
+			{Name: "F2", Number: 2, Cardinality: pref.Repeated, Kind: pref.Int64Kind, IsPacked: ptype.True},
+			{Name: "F3", Number: 3, Cardinality: pref.Repeated, Kind: pref.Sint64Kind, IsPacked: ptype.True},
+			{Name: "F4", Number: 4, Cardinality: pref.Repeated, Kind: pref.Uint64Kind, IsPacked: ptype.True},
+			{Name: "F5", Number: 5, Cardinality: pref.Repeated, Kind: pref.Fixed32Kind, IsPacked: ptype.True},
+			{Name: "F6", Number: 6, Cardinality: pref.Repeated, Kind: pref.Sfixed32Kind, IsPacked: ptype.True},
+			{Name: "F7", Number: 7, Cardinality: pref.Repeated, Kind: pref.FloatKind, IsPacked: ptype.True},
+			{Name: "F8", Number: 8, Cardinality: pref.Repeated, Kind: pref.Fixed64Kind, IsPacked: ptype.True},
+			{Name: "F9", Number: 9, Cardinality: pref.Repeated, Kind: pref.Sfixed64Kind, IsPacked: ptype.True},
+			{Name: "F10", Number: 10, Cardinality: pref.Repeated, Kind: pref.DoubleKind, IsPacked: ptype.True},
 			{Name: "F11", Number: 11, Cardinality: pref.Optional, Kind: pref.StringKind},
 			{Name: "F12", Number: 12, Cardinality: pref.Optional, Kind: pref.BytesKind},
 			{Name: "F13", Number: 13, Cardinality: pref.Optional, Kind: pref.MessageKind, MessageType: ptype.PlaceholderMessage("Message")},
@@ -44,10 +42,6 @@
 	return mtyp
 }()
 
-func packedOpt(b bool) *descriptorpb.FieldOptions {
-	return &descriptorpb.FieldOptions{Packed: &b}
-}
-
 // dhex decodes a hex-string and returns the bytes and panics if s is invalid.
 func dhex(s string) []byte {
 	b, err := hex.DecodeString(s)
diff --git a/internal/impl/message_test.go b/internal/impl/message_test.go
index f49e5c1..97fbabd 100644
--- a/internal/impl/message_test.go
+++ b/internal/impl/message_test.go
@@ -592,7 +592,8 @@
 				{Name: "key", Number: 1, Cardinality: pref.Optional, Kind: keyKind},
 				{Name: "value", Number: 2, Cardinality: pref.Optional, Kind: valKind},
 			},
-			Options: &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+			Options:    &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+			IsMapEntry: true,
 		}),
 	}
 }
@@ -1007,7 +1008,8 @@
 		{Name: "key", Number: 1, Cardinality: pref.Optional, Kind: pref.StringKind},
 		{Name: "value", Number: 2, Cardinality: pref.Optional, Kind: pref.EnumKind, EnumType: enumProto3Type},
 	},
-	Options: &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+	Options:    &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+	IsMapEntry: true,
 })
 
 var messageMapDesc = mustMakeMessageDesc(ptype.StandaloneMessage{
@@ -1017,7 +1019,8 @@
 		{Name: "key", Number: 1, Cardinality: pref.Optional, Kind: pref.StringKind},
 		{Name: "value", Number: 2, Cardinality: pref.Optional, Kind: pref.MessageKind, MessageType: scalarProto3Type.Type},
 	},
-	Options: &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+	Options:    &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+	IsMapEntry: true,
 })
 
 func (m *EnumMessages) Type() pref.MessageType            { return enumMessagesType.Type }
diff --git a/internal/legacy/message.go b/internal/legacy/message.go
index 6e77385..f4b358f 100644
--- a/internal/legacy/message.go
+++ b/internal/legacy/message.go
@@ -230,9 +230,10 @@
 			f.MessageType = mv.ProtoReflect().Type()
 		} else if t.Kind() == reflect.Map {
 			m := &ptype.StandaloneMessage{
-				Syntax:   parent.Syntax,
-				FullName: parent.FullName.Append(mapEntryName(f.Name)),
-				Options:  &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+				Syntax:     parent.Syntax,
+				FullName:   parent.FullName.Append(mapEntryName(f.Name)),
+				Options:    &descriptorpb.MessageOptions{MapEntry: scalar.Bool(true)},
+				IsMapEntry: true,
 				Fields: []ptype.Field{
 					ms.parseField(tagKey, "", "", t.Key(), nil),
 					ms.parseField(tagVal, "", "", t.Elem(), nil),
diff --git a/reflect/protodesc/protodesc.go b/reflect/protodesc/protodesc.go
index 38d03a7..e2b402b 100644
--- a/reflect/protodesc/protodesc.go
+++ b/reflect/protodesc/protodesc.go
@@ -122,13 +122,23 @@
 		var m prototype.Message
 		m.Name = protoreflect.Name(md.GetName())
 		m.Options = md.GetOptions()
+		m.IsMapEntry = md.GetOptions().GetMapEntry()
 		for _, fd := range md.GetField() {
 			var f prototype.Field
 			f.Name = protoreflect.Name(fd.GetName())
 			f.Number = protoreflect.FieldNumber(fd.GetNumber())
 			f.Cardinality = protoreflect.Cardinality(fd.GetLabel())
 			f.Kind = protoreflect.Kind(fd.GetType())
-			f.Options = fd.GetOptions()
+			opts := fd.GetOptions()
+			f.Options = opts
+			if opts != nil && opts.Packed != nil {
+				if *opts.Packed {
+					f.IsPacked = prototype.True
+				} else {
+					f.IsPacked = prototype.False
+				}
+			}
+			f.IsWeak = opts.GetWeak()
 			f.JSONName = fd.GetJsonName()
 			if fd.DefaultValue != nil {
 				f.Default, err = defval.Unmarshal(fd.GetDefaultValue(), f.Kind, defval.Descriptor)
@@ -143,7 +153,6 @@
 				}
 				f.OneofName = protoreflect.Name(md.GetOneofDecl()[i].GetName())
 			}
-			opts, _ := f.Options.(*descriptorpb.FieldOptions)
 			switch f.Kind {
 			case protoreflect.EnumKind:
 				f.EnumType, err = findEnumDescriptor(fd.GetTypeName(), r)
diff --git a/reflect/prototype/protofile.go b/reflect/prototype/protofile.go
index d7dca23..8ca96b0 100644
--- a/reflect/prototype/protofile.go
+++ b/reflect/prototype/protofile.go
@@ -11,6 +11,13 @@
 // information must be provided such as the full type name and the proto syntax.
 // When creating an entire file, the syntax and full name is derived from
 // the parent type.
+//
+// Most types contain options, defined as messages in descriptor.proto.
+// To avoid cyclic dependencies, the prototype package treats these options
+// as opaque protoreflect.ProtoMessage values. In some cases where the option
+// contains semantically important information (e.g.,
+// google.protobuf.MessageOptions.map_entry), this information must be provided
+// as a field of the corresponding type (e.g., prototype.Message.MapEntry).
 package prototype
 
 import "github.com/golang/protobuf/v2/reflect/protoreflect"
@@ -103,6 +110,7 @@
 	ExtensionRanges       [][2]protoreflect.FieldNumber
 	ExtensionRangeOptions []protoreflect.ProtoMessage
 	Options               protoreflect.ProtoMessage
+	IsMapEntry            bool
 
 	Enums      []Enum
 	Messages   []Message
@@ -131,6 +139,8 @@
 	MessageType protoreflect.MessageDescriptor
 	EnumType    protoreflect.EnumDescriptor
 	Options     protoreflect.ProtoMessage
+	IsPacked    OptionalBool
+	IsWeak      bool
 
 	*fieldMeta
 }
@@ -154,6 +164,7 @@
 	EnumType     protoreflect.EnumDescriptor
 	ExtendedType protoreflect.MessageDescriptor
 	Options      protoreflect.ProtoMessage
+	IsPacked     OptionalBool
 
 	*extensionMeta
 }
@@ -206,3 +217,13 @@
 
 	*methodMeta
 }
+
+// OptionalBool is a tristate boolean.
+type OptionalBool uint8
+
+// Tristate boolean values.
+const (
+	DefaultBool OptionalBool = iota
+	True
+	False
+)
diff --git a/reflect/prototype/protofile_type.go b/reflect/prototype/protofile_type.go
index 4e2e0c4..442ad92 100644
--- a/reflect/prototype/protofile_type.go
+++ b/reflect/prototype/protofile_type.go
@@ -165,7 +165,6 @@
 	ms messagesMeta
 	es enumsMeta
 	xs extensionsMeta
-	mo messageOptions
 }
 type messageDesc struct{ m *Message }
 
@@ -176,7 +175,7 @@
 func (t messageDesc) FullName() pref.FullName            { return t.m.fullName }
 func (t messageDesc) IsPlaceholder() bool                { return false }
 func (t messageDesc) Options() pref.ProtoMessage         { return altOptions(t.m.Options, optionTypes.Message) }
-func (t messageDesc) IsMapEntry() bool                   { return t.m.mo.lazyInit(t).isMapEntry }
+func (t messageDesc) IsMapEntry() bool                   { return t.m.IsMapEntry }
 func (t messageDesc) Fields() pref.FieldDescriptors      { return t.m.fs.lazyInit(t, t.m.Fields) }
 func (t messageDesc) Oneofs() pref.OneofDescriptors      { return t.m.os.lazyInit(t, t.m.Oneofs) }
 func (t messageDesc) ReservedNames() pref.Names          { return (*names)(&t.m.ReservedNames) }
@@ -207,22 +206,6 @@
 	return m
 }
 
-type messageOptions struct {
-	once       sync.Once
-	isMapEntry bool
-}
-
-func (p *messageOptions) lazyInit(m pref.MessageDescriptor) *messageOptions {
-	p.once.Do(func() {
-		if m.Options() != optionTypes.Message {
-			const mapEntryFieldNumber = 7 // google.protobuf.MessageOptions.map_entry
-			fs := m.Options().ProtoReflect().KnownFields()
-			p.isMapEntry = fs.Get(mapEntryFieldNumber).Bool()
-		}
-	})
-	return p
-}
-
 type fieldMeta struct {
 	inheritedMeta
 
@@ -231,25 +214,29 @@
 	ot oneofReference
 	mt messageReference
 	et enumReference
-	fo fieldOptions
 }
 type fieldDesc struct{ f *Field }
 
-func (t fieldDesc) Parent() (pref.Descriptor, bool)            { return t.f.parent, true }
-func (t fieldDesc) Index() int                                 { return t.f.index }
-func (t fieldDesc) Syntax() pref.Syntax                        { return t.f.syntax }
-func (t fieldDesc) Name() pref.Name                            { return t.f.Name }
-func (t fieldDesc) FullName() pref.FullName                    { return t.f.fullName }
-func (t fieldDesc) IsPlaceholder() bool                        { return false }
-func (t fieldDesc) Options() pref.ProtoMessage                 { return altOptions(t.f.Options, optionTypes.Field) }
-func (t fieldDesc) Number() pref.FieldNumber                   { return t.f.Number }
-func (t fieldDesc) Cardinality() pref.Cardinality              { return t.f.Cardinality }
-func (t fieldDesc) Kind() pref.Kind                            { return t.f.Kind }
-func (t fieldDesc) HasJSONName() bool                          { return t.f.JSONName != "" }
-func (t fieldDesc) JSONName() string                           { return t.f.js.lazyInit(t.f) }
-func (t fieldDesc) IsPacked() bool                             { return t.f.fo.lazyInit(t).isPacked }
-func (t fieldDesc) IsWeak() bool                               { return t.f.fo.lazyInit(t).isWeak }
-func (t fieldDesc) IsMap() bool                                { return t.f.fo.lazyInit(t).isMap }
+func (t fieldDesc) Parent() (pref.Descriptor, bool) { return t.f.parent, true }
+func (t fieldDesc) Index() int                      { return t.f.index }
+func (t fieldDesc) Syntax() pref.Syntax             { return t.f.syntax }
+func (t fieldDesc) Name() pref.Name                 { return t.f.Name }
+func (t fieldDesc) FullName() pref.FullName         { return t.f.fullName }
+func (t fieldDesc) IsPlaceholder() bool             { return false }
+func (t fieldDesc) Options() pref.ProtoMessage      { return altOptions(t.f.Options, optionTypes.Field) }
+func (t fieldDesc) Number() pref.FieldNumber        { return t.f.Number }
+func (t fieldDesc) Cardinality() pref.Cardinality   { return t.f.Cardinality }
+func (t fieldDesc) Kind() pref.Kind                 { return t.f.Kind }
+func (t fieldDesc) HasJSONName() bool               { return t.f.JSONName != "" }
+func (t fieldDesc) JSONName() string                { return t.f.js.lazyInit(t.f) }
+func (t fieldDesc) IsPacked() bool {
+	return isPacked(t.f.IsPacked, t.f.syntax, t.f.Cardinality, t.f.Kind)
+}
+func (t fieldDesc) IsWeak() bool { return t.f.IsWeak }
+func (t fieldDesc) IsMap() bool {
+	mt := t.MessageType()
+	return mt != nil && mt.IsMapEntry()
+}
 func (t fieldDesc) HasDefault() bool                           { return t.f.Default.IsValid() }
 func (t fieldDesc) Default() pref.Value                        { return t.f.dv.value(t, t.f.Default) }
 func (t fieldDesc) DefaultEnumValue() pref.EnumValueDescriptor { return t.f.dv.enum(t, t.f.Default) }
@@ -261,6 +248,20 @@
 func (t fieldDesc) ProtoType(pref.FieldDescriptor)             {}
 func (t fieldDesc) ProtoInternal(pragma.DoNotImplement)        {}
 
+func isPacked(packed OptionalBool, s pref.Syntax, c pref.Cardinality, k pref.Kind) bool {
+	if packed == False || (packed == DefaultBool && s == pref.Proto2) {
+		return false
+	}
+	if c != pref.Repeated {
+		return false
+	}
+	switch k {
+	case pref.StringKind, pref.BytesKind, pref.MessageKind, pref.GroupKind:
+		return false
+	}
+	return true
+}
+
 type jsonName struct {
 	once sync.Once
 	name string
@@ -310,77 +311,6 @@
 	return p.otyp
 }
 
-type fieldOptions struct {
-	once     sync.Once
-	isPacked bool
-	isWeak   bool
-	isMap    bool
-}
-
-func (p *fieldOptions) lazyInit(f pref.FieldDescriptor) *fieldOptions {
-	p.once.Do(func() {
-		if f.Cardinality() == pref.Repeated {
-			// In proto3, repeated fields of scalar numeric types use
-			// packed encoding by default.
-			// See https://developers.google.com/protocol-buffers/docs/proto3
-			if f.Syntax() == pref.Proto3 {
-				p.isPacked = isScalarNumeric[f.Kind()]
-			}
-			if f.Kind() == pref.MessageKind {
-				p.isMap = f.MessageType().IsMapEntry()
-			}
-		}
-
-		if f.Options() != optionTypes.Field {
-			const packedFieldNumber = 2 // google.protobuf.FieldOptions.packed
-			const weakFieldNumber = 10  // google.protobuf.FieldOptions.weak
-			fs := f.Options().ProtoReflect().KnownFields()
-			if fs.Has(packedFieldNumber) {
-				p.isPacked = fs.Get(packedFieldNumber).Bool()
-			}
-			p.isWeak = fs.Get(weakFieldNumber).Bool()
-		}
-	})
-	return p
-}
-
-// isPacked reports whether the packed options is set.
-func isPacked(m pref.ProtoMessage) (isPacked bool) {
-	if m != optionTypes.Field {
-		const packedFieldNumber = 2 // google.protobuf.FieldOptions.packed
-		fs := m.ProtoReflect().KnownFields()
-		isPacked = fs.Get(packedFieldNumber).Bool()
-	}
-	return isPacked
-}
-
-// isWeak reports whether the weak options is set.
-func isWeak(m pref.ProtoMessage) (isWeak bool) {
-	if m != optionTypes.Field {
-		const weakFieldNumber = 10 // google.protobuf.FieldOptions.weak
-		fs := m.ProtoReflect().KnownFields()
-		isWeak = fs.Get(weakFieldNumber).Bool()
-	}
-	return isWeak
-}
-
-var isScalarNumeric = map[pref.Kind]bool{
-	pref.BoolKind:     true,
-	pref.EnumKind:     true,
-	pref.Int32Kind:    true,
-	pref.Sint32Kind:   true,
-	pref.Uint32Kind:   true,
-	pref.Int64Kind:    true,
-	pref.Sint64Kind:   true,
-	pref.Uint64Kind:   true,
-	pref.Sfixed32Kind: true,
-	pref.Fixed32Kind:  true,
-	pref.FloatKind:    true,
-	pref.Sfixed64Kind: true,
-	pref.Fixed64Kind:  true,
-	pref.DoubleKind:   true,
-}
-
 type oneofMeta struct {
 	inheritedMeta
 
@@ -410,19 +340,22 @@
 }
 type extensionDesc struct{ x *Extension }
 
-func (t extensionDesc) Parent() (pref.Descriptor, bool)            { return t.x.parent, true }
-func (t extensionDesc) Syntax() pref.Syntax                        { return t.x.syntax }
-func (t extensionDesc) Index() int                                 { return t.x.index }
-func (t extensionDesc) Name() pref.Name                            { return t.x.Name }
-func (t extensionDesc) FullName() pref.FullName                    { return t.x.fullName }
-func (t extensionDesc) IsPlaceholder() bool                        { return false }
-func (t extensionDesc) Options() pref.ProtoMessage                 { return altOptions(t.x.Options, optionTypes.Field) }
-func (t extensionDesc) Number() pref.FieldNumber                   { return t.x.Number }
-func (t extensionDesc) Cardinality() pref.Cardinality              { return t.x.Cardinality }
-func (t extensionDesc) Kind() pref.Kind                            { return t.x.Kind }
-func (t extensionDesc) HasJSONName() bool                          { return false }
-func (t extensionDesc) JSONName() string                           { return "" }
-func (t extensionDesc) IsPacked() bool                             { return isPacked(t.Options()) }
+func (t extensionDesc) Parent() (pref.Descriptor, bool) { return t.x.parent, true }
+func (t extensionDesc) Syntax() pref.Syntax             { return t.x.syntax }
+func (t extensionDesc) Index() int                      { return t.x.index }
+func (t extensionDesc) Name() pref.Name                 { return t.x.Name }
+func (t extensionDesc) FullName() pref.FullName         { return t.x.fullName }
+func (t extensionDesc) IsPlaceholder() bool             { return false }
+func (t extensionDesc) Options() pref.ProtoMessage      { return altOptions(t.x.Options, optionTypes.Field) }
+func (t extensionDesc) Number() pref.FieldNumber        { return t.x.Number }
+func (t extensionDesc) Cardinality() pref.Cardinality   { return t.x.Cardinality }
+func (t extensionDesc) Kind() pref.Kind                 { return t.x.Kind }
+func (t extensionDesc) HasJSONName() bool               { return false }
+func (t extensionDesc) JSONName() string                { return "" }
+func (t extensionDesc) IsPacked() bool {
+	// Extensions always use proto2 defaults for packing.
+	return isPacked(t.x.IsPacked, pref.Proto2, t.x.Cardinality, t.x.Kind)
+}
 func (t extensionDesc) IsWeak() bool                               { return false }
 func (t extensionDesc) IsMap() bool                                { return false }
 func (t extensionDesc) HasDefault() bool                           { return t.x.Default.IsValid() }
diff --git a/reflect/prototype/standalone.go b/reflect/prototype/standalone.go
index c934c5c..4184e82 100644
--- a/reflect/prototype/standalone.go
+++ b/reflect/prototype/standalone.go
@@ -24,11 +24,11 @@
 	ExtensionRanges       [][2]protoreflect.FieldNumber
 	ExtensionRangeOptions []protoreflect.ProtoMessage
 	Options               protoreflect.ProtoMessage
+	IsMapEntry            bool
 
-	fields  fieldsMeta
-	oneofs  oneofsMeta
-	nums    numbersMeta
-	options messageOptions
+	fields fieldsMeta
+	oneofs oneofsMeta
+	nums   numbersMeta
 }
 
 // NewMessage creates a new protoreflect.MessageDescriptor.
@@ -67,7 +67,7 @@
 		for i, f := range t.Fields {
 			// Resolve placeholder messages with a concrete standalone message.
 			// If this fails, validateMessage will complain about it later.
-			if f.MessageType != nil && f.MessageType.IsPlaceholder() && !isWeak(f.Options) {
+			if f.MessageType != nil && f.MessageType.IsPlaceholder() && !f.IsWeak {
 				if m, ok := ms[f.MessageType.FullName()]; ok {
 					t.Fields[i].MessageType = m
 				}
@@ -118,6 +118,7 @@
 	EnumType     protoreflect.EnumDescriptor
 	ExtendedType protoreflect.MessageDescriptor
 	Options      protoreflect.ProtoMessage
+	IsPacked     OptionalBool
 
 	dv defaultValue
 }
diff --git a/reflect/prototype/standalone_type.go b/reflect/prototype/standalone_type.go
index 4728c4e..a087a9d 100644
--- a/reflect/prototype/standalone_type.go
+++ b/reflect/prototype/standalone_type.go
@@ -23,7 +23,7 @@
 func (t standaloneMessage) Options() pref.ProtoMessage {
 	return altOptions(t.m.Options, optionTypes.Message)
 }
-func (t standaloneMessage) IsMapEntry() bool              { return t.m.options.lazyInit(t).isMapEntry }
+func (t standaloneMessage) IsMapEntry() bool              { return t.m.IsMapEntry }
 func (t standaloneMessage) Fields() pref.FieldDescriptors { return t.m.fields.lazyInit(t, t.m.Fields) }
 func (t standaloneMessage) Oneofs() pref.OneofDescriptors { return t.m.oneofs.lazyInit(t, t.m.Oneofs) }
 func (t standaloneMessage) ReservedNames() pref.Names     { return (*names)(&t.m.ReservedNames) }
@@ -76,11 +76,13 @@
 func (t standaloneExtension) Kind() pref.Kind               { return t.x.Kind }
 func (t standaloneExtension) HasJSONName() bool             { return false }
 func (t standaloneExtension) JSONName() string              { return "" }
-func (t standaloneExtension) IsPacked() bool                { return isPacked(t.Options()) }
-func (t standaloneExtension) IsWeak() bool                  { return false }
-func (t standaloneExtension) IsMap() bool                   { return false }
-func (t standaloneExtension) HasDefault() bool              { return t.x.Default.IsValid() }
-func (t standaloneExtension) Default() pref.Value           { return t.x.dv.value(t, t.x.Default) }
+func (t standaloneExtension) IsPacked() bool {
+	return isPacked(t.x.IsPacked, pref.Proto2, t.x.Cardinality, t.x.Kind)
+}
+func (t standaloneExtension) IsWeak() bool        { return false }
+func (t standaloneExtension) IsMap() bool         { return false }
+func (t standaloneExtension) HasDefault() bool    { return t.x.Default.IsValid() }
+func (t standaloneExtension) Default() pref.Value { return t.x.dv.value(t, t.x.Default) }
 func (t standaloneExtension) DefaultEnumValue() pref.EnumValueDescriptor {
 	return t.x.dv.enum(t, t.x.Default)
 }
diff --git a/reflect/prototype/type_test.go b/reflect/prototype/type_test.go
index 4bac6c6..56edebb 100644
--- a/reflect/prototype/type_test.go
+++ b/reflect/prototype/type_test.go
@@ -41,6 +41,7 @@
 				MapEntry:   scalar.Bool(true),
 				Deprecated: scalar.Bool(true),
 			},
+			IsMapEntry: true,
 			Fields: []ptype.Field{{
 				Name:        "key", // "test.A.key"
 				Number:      1,
@@ -92,6 +93,7 @@
 				Cardinality: pref.Repeated,
 				Kind:        pref.Int32Kind,
 				Options:     &descriptorpb.FieldOptions{Packed: scalar.Bool(true)},
+				IsPacked:    ptype.True,
 			}, {
 				Name:        "field_six", // "test.B.field_six"
 				Number:      6,
@@ -132,6 +134,7 @@
 				Cardinality:  pref.Repeated,
 				Kind:         pref.MessageKind,
 				Options:      &descriptorpb.FieldOptions{Packed: scalar.Bool(false)},
+				IsPacked:     ptype.False,
 				MessageType:  ptype.PlaceholderMessage("test.C"),
 				ExtendedType: ptype.PlaceholderMessage("test.B"),
 			}},
@@ -156,6 +159,7 @@
 			Cardinality:  pref.Repeated,
 			Kind:         pref.MessageKind,
 			Options:      &descriptorpb.FieldOptions{Packed: scalar.Bool(true)},
+			IsPacked:     ptype.True,
 			MessageType:  ptype.PlaceholderMessage("test.C"),
 			ExtendedType: ptype.PlaceholderMessage("test.B"),
 		}},
@@ -601,7 +605,7 @@
 				"Number":       pref.FieldNumber(1000),
 				"Cardinality":  pref.Repeated,
 				"Kind":         pref.MessageKind,
-				"IsPacked":     true,
+				"IsPacked":     false,
 				"MessageType":  M{"FullName": pref.FullName("test.C"), "IsPlaceholder": false},
 				"ExtendedType": M{"FullName": pref.FullName("test.B"), "IsPlaceholder": false},
 				"Options":      &descriptorpb.FieldOptions{Packed: scalar.Bool(true)},
@@ -862,7 +866,6 @@
 		Number:       1000
 		Cardinality:  repeated
 		Kind:         message
-		IsPacked:     true
 		ExtendedType: test.B
 		MessageType:  test.C
 	}]
diff --git a/types/descriptor/descriptor.pb.go b/types/descriptor/descriptor.pb.go
index be51fb2..35679c3 100644
--- a/types/descriptor/descriptor.pb.go
+++ b/types/descriptor/descriptor.pb.go
@@ -3309,6 +3309,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "file",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3321,6 +3322,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "package",
@@ -3328,6 +3330,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "package",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "dependency",
@@ -3335,6 +3338,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "dependency",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "public_dependency",
@@ -3342,6 +3346,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "publicDependency",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "weak_dependency",
@@ -3349,6 +3354,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "weakDependency",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "message_type",
@@ -3356,6 +3362,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "messageType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "enum_type",
@@ -3363,6 +3370,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "enumType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "service",
@@ -3370,6 +3378,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "service",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "extension",
@@ -3377,6 +3386,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "extension",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3384,6 +3394,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "source_code_info",
@@ -3391,6 +3402,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "sourceCodeInfo",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "syntax",
@@ -3398,6 +3410,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "syntax",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3410,6 +3423,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "field",
@@ -3417,6 +3431,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "field",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "extension",
@@ -3424,6 +3439,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "extension",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "nested_type",
@@ -3431,6 +3447,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "nestedType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "enum_type",
@@ -3438,6 +3455,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "enumType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "extension_range",
@@ -3445,6 +3463,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "extensionRange",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_decl",
@@ -3452,6 +3471,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "oneofDecl",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3459,6 +3479,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "reserved_range",
@@ -3466,6 +3487,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "reservedRange",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "reserved_name",
@@ -3473,6 +3495,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "reservedName",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3485,6 +3508,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{1000, 536870912}},
@@ -3498,6 +3522,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "number",
@@ -3505,6 +3530,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "number",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "label",
@@ -3512,6 +3538,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "label",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "type",
@@ -3519,6 +3546,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "type",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "type_name",
@@ -3526,6 +3554,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "typeName",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "extendee",
@@ -3533,6 +3562,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "extendee",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "default_value",
@@ -3540,6 +3570,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "defaultValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "oneof_index",
@@ -3547,6 +3578,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "oneofIndex",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "json_name",
@@ -3554,6 +3586,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "jsonName",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3561,6 +3594,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3573,6 +3607,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3580,6 +3615,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3592,6 +3628,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "value",
@@ -3599,6 +3636,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "value",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3606,6 +3644,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "reserved_range",
@@ -3613,6 +3652,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "reservedRange",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "reserved_name",
@@ -3620,6 +3660,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "reservedName",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3632,6 +3673,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "number",
@@ -3639,6 +3681,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "number",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3646,6 +3689,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3658,6 +3702,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "method",
@@ -3665,6 +3710,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "method",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3672,6 +3718,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3684,6 +3731,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "input_type",
@@ -3691,6 +3739,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "inputType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "output_type",
@@ -3698,6 +3747,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "outputType",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -3705,6 +3755,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "client_streaming",
@@ -3713,6 +3764,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "clientStreaming",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "server_streaming",
@@ -3721,6 +3773,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "serverStreaming",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -3733,6 +3786,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "javaPackage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "java_outer_classname",
@@ -3740,6 +3794,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "javaOuterClassname",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "java_multiple_files",
@@ -3748,6 +3803,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "javaMultipleFiles",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "java_generate_equals_and_hash",
@@ -3755,6 +3811,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "javaGenerateEqualsAndHash",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "java_string_check_utf8",
@@ -3763,6 +3820,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "javaStringCheckUtf8",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "optimize_for",
@@ -3771,6 +3829,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "optimizeFor",
 				Default:     protoreflect.ValueOf(string("SPEED")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "go_package",
@@ -3778,6 +3837,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "goPackage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "cc_generic_services",
@@ -3786,6 +3846,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "ccGenericServices",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "java_generic_services",
@@ -3794,6 +3855,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "javaGenericServices",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "py_generic_services",
@@ -3802,6 +3864,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "pyGenericServices",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "php_generic_services",
@@ -3810,6 +3873,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "phpGenericServices",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "deprecated",
@@ -3818,6 +3882,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "cc_enable_arenas",
@@ -3826,6 +3891,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "ccEnableArenas",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "objc_class_prefix",
@@ -3833,6 +3899,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "objcClassPrefix",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "csharp_namespace",
@@ -3840,6 +3907,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "csharpNamespace",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "swift_prefix",
@@ -3847,6 +3915,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "swiftPrefix",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "php_class_prefix",
@@ -3854,6 +3923,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "phpClassPrefix",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "php_namespace",
@@ -3861,6 +3931,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "phpNamespace",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "php_metadata_namespace",
@@ -3868,6 +3939,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "phpMetadataNamespace",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "ruby_package",
@@ -3875,6 +3947,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "rubyPackage",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -3882,6 +3955,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ReservedRanges:  [][2]protoreflect.FieldNumber{{38, 39}},
@@ -3897,6 +3971,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "messageSetWireFormat",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "no_standard_descriptor_accessor",
@@ -3905,6 +3980,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "noStandardDescriptorAccessor",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "deprecated",
@@ -3913,6 +3989,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "map_entry",
@@ -3920,6 +3997,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "mapEntry",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -3927,6 +4005,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ReservedRanges:  [][2]protoreflect.FieldNumber{{8, 9}, {9, 10}},
@@ -3942,6 +4021,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "ctype",
 				Default:     protoreflect.ValueOf(string("STRING")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "packed",
@@ -3949,6 +4029,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "packed",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "jstype",
@@ -3957,6 +4038,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "jstype",
 				Default:     protoreflect.ValueOf(string("JS_NORMAL")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "lazy",
@@ -3965,6 +4047,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "lazy",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "deprecated",
@@ -3973,6 +4056,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "weak",
@@ -3981,6 +4065,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "weak",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -3988,6 +4073,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ReservedRanges:  [][2]protoreflect.FieldNumber{{4, 5}},
@@ -4002,6 +4088,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{1000, 536870912}},
@@ -4015,6 +4102,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "allowAlias",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "deprecated",
@@ -4023,6 +4111,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -4030,6 +4119,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ReservedRanges:  [][2]protoreflect.FieldNumber{{5, 6}},
@@ -4045,6 +4135,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -4052,6 +4143,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{1000, 536870912}},
@@ -4066,6 +4158,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -4073,6 +4166,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{1000, 536870912}},
@@ -4087,6 +4181,7 @@
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "deprecated",
 				Default:     protoreflect.ValueOf(bool(false)),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "idempotency_level",
@@ -4095,6 +4190,7 @@
 				Kind:        protoreflect.EnumKind,
 				JSONName:    "idempotencyLevel",
 				Default:     protoreflect.ValueOf(string("IDEMPOTENCY_UNKNOWN")),
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "uninterpreted_option",
@@ -4102,6 +4198,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "uninterpretedOption",
+				IsPacked:    prototype.False,
 			},
 		},
 		ExtensionRanges: [][2]protoreflect.FieldNumber{{1000, 536870912}},
@@ -4115,6 +4212,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "identifier_value",
@@ -4122,6 +4220,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "identifierValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "positive_int_value",
@@ -4129,6 +4228,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Uint64Kind,
 				JSONName:    "positiveIntValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "negative_int_value",
@@ -4136,6 +4236,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int64Kind,
 				JSONName:    "negativeIntValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "double_value",
@@ -4143,6 +4244,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.DoubleKind,
 				JSONName:    "doubleValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "string_value",
@@ -4150,6 +4252,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.BytesKind,
 				JSONName:    "stringValue",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "aggregate_value",
@@ -4157,6 +4260,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "aggregateValue",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4169,6 +4273,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "location",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4181,6 +4286,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "annotation",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4193,6 +4299,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "start",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "end",
@@ -4200,6 +4307,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "end",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "options",
@@ -4207,6 +4315,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "options",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4219,6 +4328,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "start",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "end",
@@ -4226,6 +4336,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "end",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4238,6 +4349,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "start",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "end",
@@ -4245,6 +4357,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "end",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4257,6 +4370,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "namePart",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "is_extension",
@@ -4264,6 +4378,7 @@
 				Cardinality: protoreflect.Required,
 				Kind:        protoreflect.BoolKind,
 				JSONName:    "isExtension",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4276,6 +4391,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "path",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "span",
@@ -4283,6 +4399,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "span",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "leading_comments",
@@ -4290,6 +4407,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "leadingComments",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "trailing_comments",
@@ -4297,6 +4415,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "trailingComments",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "leading_detached_comments",
@@ -4304,6 +4423,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "leadingDetachedComments",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -4316,6 +4436,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "path",
+				IsPacked:    prototype.True,
 			},
 			{
 				Name:        "source_file",
@@ -4323,6 +4444,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "sourceFile",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "begin",
@@ -4330,6 +4452,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "begin",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "end",
@@ -4337,6 +4460,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "end",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
diff --git a/types/plugin/plugin.pb.go b/types/plugin/plugin.pb.go
index b83d34a..d3c3c76 100644
--- a/types/plugin/plugin.pb.go
+++ b/types/plugin/plugin.pb.go
@@ -498,6 +498,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "major",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "minor",
@@ -505,6 +506,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "minor",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "patch",
@@ -512,6 +514,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.Int32Kind,
 				JSONName:    "patch",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "suffix",
@@ -519,6 +522,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "suffix",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -531,6 +535,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "fileToGenerate",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "parameter",
@@ -538,6 +543,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "parameter",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "proto_file",
@@ -545,6 +551,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "protoFile",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "compiler_version",
@@ -552,6 +559,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "compilerVersion",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -564,6 +572,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "error",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "file",
@@ -571,6 +580,7 @@
 				Cardinality: protoreflect.Repeated,
 				Kind:        protoreflect.MessageKind,
 				JSONName:    "file",
+				IsPacked:    prototype.False,
 			},
 		},
 	},
@@ -583,6 +593,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "name",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "insertion_point",
@@ -590,6 +601,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "insertionPoint",
+				IsPacked:    prototype.False,
 			},
 			{
 				Name:        "content",
@@ -597,6 +609,7 @@
 				Cardinality: protoreflect.Optional,
 				Kind:        protoreflect.StringKind,
 				JSONName:    "content",
+				IsPacked:    prototype.False,
 			},
 		},
 	},