diff --git a/stdlib/@python2/ctypes/__init__.pyi b/stdlib/@python2/ctypes/__init__.pyi
index 33184cc2f..8a10ff954 100644
--- a/stdlib/@python2/ctypes/__init__.pyi
+++ b/stdlib/@python2/ctypes/__init__.pyi
@@ -150,7 +150,7 @@ def create_unicode_buffer(init: _UnionT[int, Text], size: int | None = ...) -> A
 if sys.platform == "win32":
     def DllCanUnloadNow() -> int: ...
     def DllGetClassObject(rclsid: Any, riid: Any, ppv: Any) -> int: ...  # TODO not documented
-    def FormatError(code: int) -> str: ...
+    def FormatError(code: int = ...) -> str: ...
     def GetLastError() -> int: ...
 
 def get_errno() -> int: ...
diff --git a/stdlib/ctypes/__init__.pyi b/stdlib/ctypes/__init__.pyi
index b76c59bec..5cf8ce289 100644
--- a/stdlib/ctypes/__init__.pyi
+++ b/stdlib/ctypes/__init__.pyi
@@ -158,7 +158,7 @@ def create_unicode_buffer(init: int | str, size: int | None = ...) -> Array[c_wc
 if sys.platform == "win32":
     def DllCanUnloadNow() -> int: ...
     def DllGetClassObject(rclsid: Any, riid: Any, ppv: Any) -> int: ...  # TODO not documented
-    def FormatError(code: int) -> str: ...
+    def FormatError(code: int = ...) -> str: ...
     def GetLastError() -> int: ...
 
 def get_errno() -> int: ...