diff --git a/graphene/utils/annotate.py b/graphene/utils/annotate.py
index b55c3d6c..51a87a78 100644
--- a/graphene/utils/annotate.py
+++ b/graphene/utils/annotate.py
@@ -33,5 +33,4 @@ def annotate(_func=None, _trigger_warning=True, **annotations):
     else:
         _func.__annotations__.update(annotations)
 
-    _func._is_annotated = True
     return _func