diff --git a/builtins/2.7/_functools.pyi b/builtins/2.7/_functools.pyi
index 9ac938eff..ceb3870d0 100644
--- a/builtins/2.7/_functools.pyi
+++ b/builtins/2.7/_functools.pyi
@@ -1,6 +1,6 @@
 """Stub file for the '_functools' module."""
 
-from typing import Any, Callable
+from typing import Any, Callable, Iterator, Optional, TypeVar
 
 _T = TypeVar("T")
 def reduce(function: Callable[[_T, _T], _T],
diff --git a/builtins/3/atexit.pyi b/builtins/3/atexit.pyi
index 62aeaea27..683b6c56e 100644
--- a/builtins/3/atexit.pyi
+++ b/builtins/3/atexit.pyi
@@ -1,18 +1,7 @@
 """Stub file for the 'atexit' module."""
-# This is an autogenerated file. It serves as a starting point
-# for a more precise manual annotation of this module.
-# Feel free to edit the source below, but remove this header when you do.
-
-from typing import Any, List, Tuple, Dict, Generic
 
 def _clear() -> None: ...
-
-def _ncallbacks() -> long: ...
-
+def _ncallbacks() -> int: ...
 def _run_exitfuncs() -> None: ...
-
-def register(*args, **kwargs) -> Any:
-    raise MemoryError()
-    raise TypeError()
-
-def unregister(*args, **kwargs) -> None: ...
+def register(func: Callable[..., Any], *args, **kwargs) -> Callable[..., Any]: ...
+def unregister(func: Callable[..., Any]) -> None: ...