--- contrib/python/Werkzeug/py3/werkzeug/local.py	(index)
+++ contrib/python/Werkzeug/py3/werkzeug/local.py	(working tree)
@@ -541,7 +541,7 @@ class LocalProxy:
         The class can be instantiated with a callable.
     """
 
-    __slots__ = ("__local", "__name", "__wrapped__")
+    __slots__ = ("__local", "__name", "__wrapped__", "__dict__")
 
     def __init__(
         self,