diff -r 10942ed172de -r 54b8a1f249fb server/hook.py
--- a/server/hook.py	Tue Sep 15 16:15:03 2015 +0200
+++ b/server/hook.py	Tue Oct 13 15:09:22 2015 +0200
@@ -391,7 +391,7 @@
 
 
     def filtered_possible_objects(self, pruned, *args, **kwargs):
-        for appobjects in self.itervalues():
+        for appobjects in self.values():
             if pruned:
                 filtered_objects = [obj for obj in appobjects if obj not in pruned]
                 if not filtered_objects: