diff --git a/src/oop_ext/foundation/callback/_callback.py b/src/oop_ext/foundation/callback/_callback.py
index 34043b8..412297f 100644
--- a/src/oop_ext/foundation/callback/_callback.py
+++ b/src/oop_ext/foundation/callback/_callback.py
@@ -392,7 +392,6 @@ def Contains(
         real_func: Optional[Callable] = func
 
         if isinstance(real_func, WeakMethodProxy):
-            real_func = cast(WeakMethodProxy, real_func)
             real_func = real_func.GetWrappedFunction()
 
         # We must check if it's actually the same, because it may be that the ids we've gotten for