diff --git a/lib/pystray/_util/win32.py b/lib/pystray/_util/win32.py
index c053e9d..e9a8f23 100644
--- a/lib/pystray/_util/win32.py
+++ b/lib/pystray/_util/win32.py
@@ -346,7 +346,7 @@ def _err(result, func, arguments):
     ChangeWindowMessageFilterEx.restype = wintypes.BOOL
     ChangeWindowMessageFilterEx.errcheck = _err
 
-except KeyError:
+except (KeyError, AttributeError):
     def ChangeWindowMessageFilterEx(
             hWnd, message, action, pCHangeFilterStruct):
         """A dummy implementation of ``ChangeWindowMessageFilterEx`` always