diff --git a/stdlib/2/typing.pyi b/stdlib/2/typing.pyi
index d95f7b26c..6c159b963 100644
--- a/stdlib/2/typing.pyi
+++ b/stdlib/2/typing.pyi
@@ -237,9 +237,9 @@ class ValuesView(MappingView, Iterable[_VT_co], Generic[_VT_co]):
 @runtime
 class ContextManager(Protocol[_T_co]):
     def __enter__(self) -> _T_co: ...
-    def __exit__(self, exc_type: Optional[Type[BaseException]],
-                 exc_value: Optional[BaseException],
-                 traceback: Optional[TracebackType]) -> Optional[bool]: ...
+    def __exit__(self, __exc_type: Optional[Type[BaseException]],
+                 __exc_value: Optional[BaseException],
+                 __traceback: Optional[TracebackType]) -> Optional[bool]: ...
 
 class Mapping(Iterable[_KT], Container[_KT], Generic[_KT, _VT_co]):
     # TODO: We wish the key type could also be covariant, but that doesn't work,
diff --git a/stdlib/3/typing.pyi b/stdlib/3/typing.pyi
index 04579dd68..c99c1f99a 100644
--- a/stdlib/3/typing.pyi
+++ b/stdlib/3/typing.pyi
@@ -353,9 +353,9 @@ class ValuesView(MappingView, Iterable[_VT_co], Generic[_VT_co]):
 @runtime
 class ContextManager(Protocol[_T_co]):
     def __enter__(self) -> _T_co: ...
-    def __exit__(self, exc_type: Optional[Type[BaseException]],
-                 exc_value: Optional[BaseException],
-                 traceback: Optional[TracebackType]) -> Optional[bool]: ...
+    def __exit__(self, __exc_type: Optional[Type[BaseException]],
+                 __exc_value: Optional[BaseException],
+                 __traceback: Optional[TracebackType]) -> Optional[bool]: ...
 
 if sys.version_info >= (3, 5):
     @runtime