diff --git a/include/clang-c/Index.h b/include/clang-c/Index.h
index fa35d05..75ad31a 100644
--- a/include/clang-c/Index.h
+++ b/include/clang-c/Index.h
@@ -810,7 +810,8 @@
 
   CXCursor_IBActionAttr                  = 401,
   CXCursor_IBOutletAttr                  = 402,
-  CXCursor_LastAttr                      = CXCursor_IBOutletAttr,
+  CXCursor_IBOutletCollectionAttr        = 403,
+  CXCursor_LastAttr                      = CXCursor_IBOutletCollectionAttr,
      
   /* Preprocessing */
   CXCursor_PreprocessingDirective        = 500,
diff --git a/include/clang/AST/Attr.h b/include/clang/AST/Attr.h
index 6bdb4a2..f41fbf9 100644
--- a/include/clang/AST/Attr.h
+++ b/include/clang/AST/Attr.h
@@ -23,9 +23,10 @@
 
 namespace clang {
   class ASTContext;
+  class IdentifierInfo;
+  class ObjCInterfaceDecl;
 }
 
-
 // Defined in ASTContext.h
 void *operator new(size_t Bytes, clang::ASTContext &C,
                    size_t Alignment = 16) throw ();
@@ -63,6 +64,7 @@
     GNUInline,
     Hiding,
     IBOutletKind, // Clang-specific. Use "Kind" suffix to not conflict w/ macro.
+    IBOutletCollectionKind, // Clang-specific.
     IBActionKind, // Clang-specific. Use "Kind" suffix to not conflict w/ macro.
     Malloc,
     NoDebug,
@@ -318,6 +320,23 @@
   static bool classof(const IBOutletAttr *A) { return true; }
 };
 
+class IBOutletCollectionAttr : public Attr {
+  const ObjCInterfaceDecl *D;
+public:
+  IBOutletCollectionAttr(const ObjCInterfaceDecl *d = 0)
+    : Attr(IBOutletCollectionKind), D(d) {}
+
+  const ObjCInterfaceDecl *getClass() const { return D; }
+
+  virtual Attr *clone(ASTContext &C) const;
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Attr *A) {
+    return A->getKind() == IBOutletCollectionKind;
+  }
+  static bool classof(const IBOutletCollectionAttr *A) { return true; }
+};
+
 class IBActionAttr : public Attr {
 public:
   IBActionAttr() : Attr(IBActionKind) {}
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 2298f6a..03c9c0e 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -957,8 +957,7 @@
 
 // Clang-Specific Attributes
 def err_attribute_iboutlet : Error<
-  "iboutlet attribute can only be applied to instance variables or "
-  "properties">;
+  "%0 attribute can only be applied to instance variables or properties">;
 def err_attribute_ibaction: Error<
   "ibaction attribute can only be applied to Objective-C instance methods">;
 def err_attribute_overloadable_not_function : Error<
diff --git a/include/clang/Parse/AttributeList.h b/include/clang/Parse/AttributeList.h
index 68d6f22..1e6d3ab 100644
--- a/include/clang/Parse/AttributeList.h
+++ b/include/clang/Parse/AttributeList.h
@@ -55,6 +55,7 @@
   enum Kind {             // Please keep this list alphabetized.
     AT_IBAction,          // Clang-specific.
     AT_IBOutlet,          // Clang-specific.
+    AT_IBOutletCollection, // Clang-specific.
     AT_address_space,
     AT_alias,
     AT_aligned,
diff --git a/lib/AST/AttrImpl.cpp b/lib/AST/AttrImpl.cpp
index 0345226..1f3510d 100644
--- a/lib/AST/AttrImpl.cpp
+++ b/lib/AST/AttrImpl.cpp
@@ -143,6 +143,10 @@
   return ::new (C) IBOutletAttr;
 }
 
+Attr *IBOutletCollectionAttr::clone(ASTContext &C) const {
+  return ::new (C) IBOutletCollectionAttr(D);
+}
+
 Attr *IBActionAttr::clone(ASTContext &C) const {
   return ::new (C) IBActionAttr;
 }
diff --git a/lib/Checker/CheckObjCDealloc.cpp b/lib/Checker/CheckObjCDealloc.cpp
index c23be87..11ddaca 100644
--- a/lib/Checker/CheckObjCDealloc.cpp
+++ b/lib/Checker/CheckObjCDealloc.cpp
@@ -115,7 +115,8 @@
     QualType T = ID->getType();
 
     if (!T->isObjCObjectPointerType() ||
-        ID->getAttr<IBOutletAttr>()) // Skip IBOutlets.
+        ID->getAttr<IBOutletAttr>() || // Skip IBOutlets.
+        ID->getAttr<IBOutletCollectionAttr>()) // Skip IBOutletCollections.
       continue;
 
     containsPointerIvar = true;
diff --git a/lib/Checker/ObjCUnusedIVarsChecker.cpp b/lib/Checker/ObjCUnusedIVarsChecker.cpp
index 0e47621..2523cff 100644
--- a/lib/Checker/ObjCUnusedIVarsChecker.cpp
+++ b/lib/Checker/ObjCUnusedIVarsChecker.cpp
@@ -114,7 +114,8 @@
     // (b) explicitly marked unused
     // (c) are iboutlets
     if (ID->getAccessControl() != ObjCIvarDecl::Private ||
-        ID->getAttr<UnusedAttr>() || ID->getAttr<IBOutletAttr>())
+        ID->getAttr<UnusedAttr>() || ID->getAttr<IBOutletAttr>() ||
+        ID->getAttr<IBOutletCollectionAttr>())
       continue;
 
     M[ID] = Unused;
diff --git a/lib/Frontend/PCHReaderDecl.cpp b/lib/Frontend/PCHReaderDecl.cpp
index 1e8bd2f..0aee70c 100644
--- a/lib/Frontend/PCHReaderDecl.cpp
+++ b/lib/Frontend/PCHReaderDecl.cpp
@@ -726,6 +726,13 @@
       New = ::new (*Context) IBOutletAttr();
       break;
 
+    case Attr::IBOutletCollectionKind: {
+      ObjCInterfaceDecl *D =
+        cast_or_null<ObjCInterfaceDecl>(GetDecl(Record[Idx++]));
+      New = ::new (*Context) IBOutletCollectionAttr(D);
+      break;
+    }
+
     SIMPLE_ATTR(Malloc);
     SIMPLE_ATTR(NoDebug);
     SIMPLE_ATTR(NoInline);
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 88d1972..f8415cd 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1917,6 +1917,12 @@
     case Attr::NoThrow:
       break;
 
+    case Attr::IBOutletCollectionKind: {
+      const IBOutletCollectionAttr *ICA = cast<IBOutletCollectionAttr>(Attr);
+      AddDeclRef(ICA->getClass(), Record);
+      break;
+    }
+
     case Attr::NonNull: {
       const NonNullAttr *NonNull = cast<NonNullAttr>(Attr);
       Record.push_back(NonNull->size());
diff --git a/lib/Parse/AttributeList.cpp b/lib/Parse/AttributeList.cpp
index 5340628..1ebff22 100644
--- a/lib/Parse/AttributeList.cpp
+++ b/lib/Parse/AttributeList.cpp
@@ -84,6 +84,7 @@
     .Case("fastcall", AT_fastcall)
     .Case("ibaction", AT_IBAction)
     .Case("iboutlet", AT_IBOutlet)
+    .Case("iboutletcollection", AT_IBOutletCollection)
     .Case("noreturn", AT_noreturn)
     .Case("noinline", AT_noinline)
     .Case("override", AT_override)
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 3ae681a..c6dcc3b 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -259,6 +259,26 @@
   S.Diag(Attr.getLoc(), diag::err_attribute_iboutlet) << Attr.getName();
 }
 
+static void HandleIBOutletCollection(Decl *d, const AttributeList &Attr,
+                                     Sema &S) {
+
+  // The iboutletcollection attribute can have zero or one arguments.
+  if (Attr.getNumArgs() > 1) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
+    return;
+  }
+
+  // The IBOutletCollection attributes only apply to instance variables of
+  // Objective-C classes.
+  if (!(isa<ObjCIvarDecl>(d) || isa<ObjCPropertyDecl>(d))) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_iboutlet) << Attr.getName();
+    return;
+  }
+
+  // FIXME: Eventually accept the type argument.
+  d->addAttr(::new (S.Context) IBOutletCollectionAttr());
+}
+
 static void HandleNonNullAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   // GCC ignores the nonnull attribute on K&R style function prototypes, so we
   // ignore it as well
@@ -1884,7 +1904,9 @@
     return;
   switch (Attr.getKind()) {
   case AttributeList::AT_IBAction:            HandleIBAction(D, Attr, S); break;
-  case AttributeList::AT_IBOutlet:            HandleIBOutlet(D, Attr, S); break;
+    case AttributeList::AT_IBOutlet:          HandleIBOutlet(D, Attr, S); break;
+  case AttributeList::AT_IBOutletCollection:
+      HandleIBOutletCollection(D, Attr, S); break;
   case AttributeList::AT_address_space:
   case AttributeList::AT_objc_gc:
   case AttributeList::AT_vector_size:
diff --git a/test/Index/c-index-api-loadTU-test.m b/test/Index/c-index-api-loadTU-test.m
index d97f963..22875db 100644
--- a/test/Index/c-index-api-loadTU-test.m
+++ b/test/Index/c-index-api-loadTU-test.m
@@ -54,6 +54,18 @@
   main(someEnum, (const char **)bee);
 }
 
+// Test attribute traversal.
+#define IBOutlet __attribute__((iboutlet))
+#define IBOutletCollection(ClassName) __attribute__((iboutletcollection))
+#define IBAction void)__attribute__((ibaction)
+
+@interface TestAttributes {
+  IBOutlet char * anOutlet;
+  IBOutletCollection(id) id anOutletCollection;
+}
+- (IBAction) actionMethod:(id)arg;
+@end
+
 // CHECK: c-index-api-loadTU-test.m:4:12: ObjCInterfaceDecl=Foo:4:12 Extent=[4:1 - 12:5]
 // CHECK: c-index-api-loadTU-test.m:6:32: ObjCIvarDecl=myoutlet:6:32 (Definition) Extent=[6:32 - 6:40]
 // CHECK: <invalid loc>:0:0: attribute(iboutlet)=
@@ -123,4 +135,14 @@
 // CHECK: c-index-api-loadTU-test.m:54:8: DeclRefExpr=someEnum:43:3 Extent=[54:8 - 54:16]
 // CHECK: c-index-api-loadTU-test.m:54:18: UnexposedExpr=bee:47:8 Extent=[54:18 - 54:36]
 // CHECK: c-index-api-loadTU-test.m:54:33: DeclRefExpr=bee:47:8 Extent=[54:33 - 54:36]
+// CHECK: c-index-api-loadTU-test.m:62:12: ObjCInterfaceDecl=TestAttributes:62:12 Extent=[62:1 - 67:5]
+// CHECK: c-index-api-loadTU-test.m:63:19: ObjCIvarDecl=anOutlet:63:19 (Definition) Extent=[63:19 - 63:27]
+// CHECK: <invalid loc>:0:0: attribute(iboutlet)=
+// CHECK: c-index-api-loadTU-test.m:64:29: ObjCIvarDecl=anOutletCollection:64:29 (Definition) Extent=[64:29 - 64:47]
+// CHECK: <invalid loc>:0:0: attribute(iboutletcollection)=
+// CHECK: c-index-api-loadTU-test.m:64:26: TypeRef=id:0:0 Extent=[64:26 - 64:28]
+// CHECK: c-index-api-loadTU-test.m:66:1: ObjCInstanceMethodDecl=actionMethod::66:1 Extent=[66:1 - 66:35]
+// CHECK: <invalid loc>:0:0: attribute(ibaction)=
+// CHECK: c-index-api-loadTU-test.m:66:31: ParmDecl=arg:66:31 (Definition) Extent=[66:28 - 66:34]
+// CHECK: c-index-api-loadTU-test.m:66:28: TypeRef=id:0:0 Extent=[66:28 - 66:30]
 
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 85383d0..563dd6b 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -1726,6 +1726,8 @@
       return createCXString("attribute(ibaction)");
   case CXCursor_IBOutletAttr:
      return createCXString("attribute(iboutlet)");
+  case CXCursor_IBOutletCollectionAttr:
+      return createCXString("attribute(iboutletcollection)");
   case CXCursor_PreprocessingDirective:
     return createCXString("preprocessing directive");
   case CXCursor_MacroDefinition:
diff --git a/tools/libclang/CXCursor.cpp b/tools/libclang/CXCursor.cpp
index dea7b4d..f7192dd 100644
--- a/tools/libclang/CXCursor.cpp
+++ b/tools/libclang/CXCursor.cpp
@@ -80,6 +80,7 @@
     default: break;
     case Attr::IBActionKind: return CXCursor_IBActionAttr;
     case Attr::IBOutletKind: return CXCursor_IBOutletAttr;
+    case Attr::IBOutletCollectionKind: return CXCursor_IBOutletCollectionAttr;
   }
 
   return CXCursor_UnexposedAttr;