diff --git a/plone/app/discussion/conversation.py b/plone/app/discussion/conversation.py
index b28054f..2f824d6 100644
--- a/plone/app/discussion/conversation.py
+++ b/plone/app/discussion/conversation.py
@@ -167,7 +167,8 @@ class Conversation(Traversable, Persistent, Explicit):
 
     @property
     def commentators(self):
-        return self._commentators.keys()
+        if len(self._commentators.keys()) != 0:
+            return self._commentators.keys()
 
     def objectIds(self):
         return self._comments.keys()