diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index f4d8683..5cf9ad1 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2222,12 +2222,12 @@
 }
 
 PyDoc_STRVAR(dictionary_doc,
-"dict() -> new empty dictionary.\n"
+"dict() -> new empty dictionary\n"
 "dict(mapping) -> new dictionary initialized from a mapping object's\n"
-"    (key, value) pairs.\n"
-"dict(seq) -> new dictionary initialized as if via:\n"
+"    (key, value) pairs\n"
+"dict(iterable) -> new dictionary initialized as if via:\n"
 "    d = {}\n"
-"    for k, v in seq:\n"
+"    for k, v in iterable:\n"
 "        d[k] = v\n"
 "dict(**kwargs) -> new dictionary initialized with the name=value pairs\n"
 "    in the keyword argument list.  For example:  dict(one=1, two=2)");
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 9f35d9d..6188bec 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2516,8 +2516,8 @@
 };
 
 PyDoc_STRVAR(list_doc,
-"list() -> new list\n"
-"list(sequence) -> new list initialized from sequence's items");
+"list() -> new empty list\n"
+"list(iterable) -> new list initialized from iterable's items");
 
 
 static PyObject *
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 81fd315..af5d576 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -2102,7 +2102,8 @@
 };
 
 PyDoc_STRVAR(set_doc,
-"set(iterable) --> set object\n\
+"set() -> new empty set object\n\
+set(iterable) -> new set object\n\
 \n\
 Build an unordered collection of unique elements.");
 
@@ -2200,7 +2201,8 @@
 };
 
 PyDoc_STRVAR(frozenset_doc,
-"frozenset(iterable) --> frozenset object\n\
+"frozenset() -> empty frozenset object\n\
+frozenset(iterable) -> frozenset object\n\
 \n\
 Build an immutable unordered collection of unique elements.");
 
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index b1a7003..92fc1f4 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -630,10 +630,10 @@
 }
 
 PyDoc_STRVAR(tuple_doc,
-"tuple() -> an empty tuple\n"
-"tuple(sequence) -> tuple initialized from sequence's items\n"
-"\n"
-"If the argument is a tuple, the return value is the same object.");
+"tuple() -> empty tuple\n\
+tuple(iterable) -> tuple initialized from iterable's items\n\
+\n\
+If the argument is a tuple, the return value is the same object.");
 
 static PySequenceMethods tuple_as_sequence = {
 	(lenfunc)tuplelength,			/* sq_length */