diff --git a/third_party/2and3/mypy_extensions.pyi b/third_party/2and3/mypy_extensions.pyi
index 1c5b46b9c56f..f9c9ff6da6c0 100644
--- a/third_party/2and3/mypy_extensions.pyi
+++ b/third_party/2and3/mypy_extensions.pyi
@@ -17,7 +17,7 @@ class _TypedDict(Mapping[str, object], metaclass=abc.ABCMeta):
     def pop(self, k: NoReturn, default: _T = ...) -> object: ...
     def update(self: _T, __m: _T) -> None: ...
     if sys.version_info < (3, 0):
-        def has_key(self) -> bool: ...
+        def has_key(self, k: str) -> bool: ...
         def viewitems(self) -> ItemsView[str, object]: ...
         def viewkeys(self) -> KeysView[str]: ...
         def viewvalues(self) -> ValuesView[object]: ...