diff --git a/admin_interface/compat.py b/admin_interface/compat.py
index 3501b7f..f47359c 100644
--- a/admin_interface/compat.py
+++ b/admin_interface/compat.py
@@ -15,3 +15,4 @@ else:
     def FileExtensionValidator(*args, **kwargs):
         def noop(*args, **kwargs):
             pass
+        return noop