diff --git a/naive-nlu/tree_nlu/knowledge_evaluation.py b/naive-nlu/tree_nlu/knowledge_evaluation.py
index 6651050..2feb42c 100644
--- a/naive-nlu/tree_nlu/knowledge_evaluation.py
+++ b/naive-nlu/tree_nlu/knowledge_evaluation.py
@@ -111,8 +111,8 @@ def modifiable_element_for_existance_in_set(container, set_name, element):
         return (set_name in container) and (element in container[set_name])
 
     def setter():
-        logging.debug("  add({} {} {})".format(container, set_name, element))
         nonlocal container, set_name, element
+        logging.debug("  add({} {} {})".format(container, set_name, element))
         return container[set_name].add(element)
 
     return ModifiableProperty(