diff --git a/stdlib/2.7/UserList.pyi b/stdlib/2.7/UserList.pyi
new file mode 100644
index 000000000..4f31b93b0
--- /dev/null
+++ b/stdlib/2.7/UserList.pyi
@@ -0,0 +1,3 @@
+import collections
+
+class UserList(collections.MutableSequence): ...
diff --git a/stdlib/2.7/UserString.pyi b/stdlib/2.7/UserString.pyi
new file mode 100644
index 000000000..d2a33c32a
--- /dev/null
+++ b/stdlib/2.7/UserString.pyi
@@ -0,0 +1,4 @@
+import collections
+
+class UserString(collections.Sequence): ...
+class MutableString(UserString, collections.MutableSequence): ...
\ No newline at end of file
diff --git a/stdlib/2.7/collections.pyi b/stdlib/2.7/collections.pyi
index ab40403a6..69f13677a 100644
--- a/stdlib/2.7/collections.pyi
+++ b/stdlib/2.7/collections.pyi
@@ -2,16 +2,13 @@
 
 # Based on http://docs.python.org/2.7/library/collections.html
 
-# TODO UserDict
-# TODO UserList
-# TODO UserString
 # TODO more abstract base classes (interfaces in mypy)
 
 # NOTE: These are incomplete!
 
 from typing import (
     Dict, Generic, TypeVar, Iterable, Tuple, Callable, Mapping, overload, Iterator, Sized,
-    Optional, List, Set, Sequence, Union, Reversible
+    Optional, List, Set, Sequence, Union, Reversible, MutableMapping, MutableSequence
 )
 import typing
 
@@ -22,8 +19,6 @@ _VT = TypeVar('_VT')
 # namedtuple is special-cased in the type checker; the initializer is ignored.
 namedtuple = object()
 
-MutableMapping = typing.MutableMapping
-
 class deque(Sized, Iterable[_T], Reversible[_T], Generic[_T]):
     def __init__(self, iterable: Iterable[_T] = ...,
                  maxlen: int = ...) -> None: ...
diff --git a/stdlib/3/collections.pyi b/stdlib/3/collections.pyi
index 956cb286f..4939e9268 100644
--- a/stdlib/3/collections.pyi
+++ b/stdlib/3/collections.pyi
@@ -2,9 +2,6 @@
 
 # Based on http://docs.python.org/3.2/library/collections.html
 
-# TODO UserDict
-# TODO UserList
-# TODO UserString
 # TODO more abstract base classes (interfaces in mypy)
 
 # These are not exported.
@@ -30,6 +27,10 @@ _VT = TypeVar('_VT')
 # namedtuple is special-cased in the type checker; the initializer is ignored.
 namedtuple = object()
 
+class UserDict(MutableMapping): ...
+class UserList(MutableSequence): ...
+class UserString(Sequence): ...
+class MutableString(UserString, MutableSequence): ...
 
 # Technically, deque only derives from MutableSequence in 3.5.
 # But in practice it's not worth losing sleep over.
diff --git a/third_party/2.7/six/moves/__init__.pyi b/third_party/2.7/six/moves/__init__.pyi
index 827ee8a5d..1347e7510 100644
--- a/third_party/2.7/six/moves/__init__.pyi
+++ b/third_party/2.7/six/moves/__init__.pyi
@@ -14,8 +14,8 @@ from __builtin__ import reduce as reduce
 from pipes import quote as shlex_quote
 from StringIO import StringIO as StringIO
 from UserDict import UserDict as UserDict
-## from UserList import UserList as UserList
-## from UserString import UserString as UserString
+from UserList import UserList as UserList
+from UserString import UserString as UserString
 from __builtin__ import xrange as xrange
 from itertools import izip as zip
 from itertools import izip_longest as zip_longest
diff --git a/third_party/3/six/moves/__init__.pyi b/third_party/3/six/moves/__init__.pyi
index 4f41143e9..49cf9bcab 100644
--- a/third_party/3/six/moves/__init__.pyi
+++ b/third_party/3/six/moves/__init__.pyi
@@ -16,9 +16,9 @@ from imp import reload as reload_module
 from functools import reduce as reduce
 from shlex import quote as shlex_quote
 from io import StringIO as StringIO
-# from collections import UserDict as UserDict
-# from collections import UserList as UserList
-# from collections import UserString as UserString
+from collections import UserDict as UserDict
+from collections import UserList as UserList
+from collections import UserString as UserString
 from builtins import range as xrange
 from builtins import zip as zip
 from itertools import zip_longest as zip_longest