diff --git a/third_party/2.7/six/__init__.pyi b/third_party/2.7/six/__init__.pyi
index 0f6acfc73..5f5383bbc 100644
--- a/third_party/2.7/six/__init__.pyi
+++ b/third_party/2.7/six/__init__.pyi
@@ -77,7 +77,7 @@ def assertRaisesRegex(self: unittest.TestCase, msg: str = ...) -> Any: ...
 def assertRaisesRegex(self: unittest.TestCase, callable_obj: Callable[..., Any], *args: Any, **kwargs: Any) -> Any: ...
 def assertRegex(self: unittest.TestCase, text: AnyStr, expected_regex: Union[AnyStr, Pattern[AnyStr]], msg: str = ...) -> None: ...
 
-def reraise(tp: type, value: Optional[BaseException], tb: types.TracebackType = ...) -> None: ...
+def reraise(tp: type, value: Optional[BaseException], tb: Optional[types.TracebackType] = ...) -> None: ...
 def exec_(_code_: Union[unicode, types.CodeType], _globs_: Dict[str, Any] = ..., _locs_: Dict[str, Any] = ...): ...
 def raise_from(value: BaseException, from_value: BaseException) -> None: ...
 
diff --git a/third_party/3/six/__init__.pyi b/third_party/3/six/__init__.pyi
index 0607cc18f..0e7eb93e1 100644
--- a/third_party/3/six/__init__.pyi
+++ b/third_party/3/six/__init__.pyi
@@ -91,7 +91,7 @@ def assertRegex(self: unittest.TestCase, text: AnyStr, expected_regex: Union[Any
 
 exec_ = exec
 
-def reraise(tp: type, value: Optional[BaseException], tb: types.TracebackType = None) -> None: ...
+def reraise(tp: type, value: Optional[BaseException], tb: Optional[types.TracebackType] = None) -> None: ...
 def raise_from(value: BaseException, from_value: BaseException) -> None: ...
 
 print_ = print