diff --git a/third_party/2and3/flask/app.pyi b/third_party/2and3/flask/app.pyi
index 564269273..a71e7d81b 100644
--- a/third_party/2and3/flask/app.pyi
+++ b/third_party/2and3/flask/app.pyi
@@ -83,7 +83,7 @@ class Flask(_PackageBoundObject):
     session_interface: Any = ...
     import_name: str = ...
     template_folder: str = ...
-    root_path: Optional[Union[str, Text]] = ...
+    root_path: Union[str, Text] = ...
     static_url_path: Any = ...
     static_folder: Optional[str] = ...
     instance_path: Union[str, Text] = ...