diff --git a/stdlib/3/os/__init__.pyi b/stdlib/3/os/__init__.pyi
index b46681e9c..9e31baeae 100644
--- a/stdlib/3/os/__init__.pyi
+++ b/stdlib/3/os/__init__.pyi
@@ -840,6 +840,7 @@ if sys.version_info >= (3, 8):
     if sys.platform == "win32":
         class _AddedDllDirectory:
             path: Optional[str]
+            def __init__(self, path: Optional[str], cookie: _T, remove_dll_directory: Callable[[_T], Any]) -> None: ...
             def close(self) -> None: ...
             def __enter__(self: _T) -> _T: ...
             def __exit__(self, *args: Any) -> None: ...
diff --git a/tests/stubtest_whitelists/win32-py38.txt b/tests/stubtest_whitelists/win32-py38.txt
index 6927638e4..f375ee5ec 100644
--- a/tests/stubtest_whitelists/win32-py38.txt
+++ b/tests/stubtest_whitelists/win32-py38.txt
@@ -1,2 +1 @@
-os._AddedDllDirectory.__init__  # Parameters mismatch
-importlib.metadata.DistributionFinder.Context.pattern
\ No newline at end of file
+importlib.metadata.DistributionFinder.Context.pattern