diff --git a/src/tmp/wokkel/rsm.py b/src/tmp/wokkel/rsm.py
index 5ece518e..d017f598 100644
--- a/src/tmp/wokkel/rsm.py
+++ b/src/tmp/wokkel/rsm.py
@@ -388,8 +388,9 @@ class PubSubClient(pubsub.PubSubClient):
         def cb(iq):
             items = []
             pubsub_elt = iq.pubsub
-            for element in pubsub_elt.items.elements(pubsub.NS_PUBSUB, 'item'):
-                items.append(element)
+            if pubsub_elt.items:
+                for element in pubsub_elt.items.elements(pubsub.NS_PUBSUB, 'item'):
+                    items.append(element)
 
             try:
                 rsm_response = RSMResponse.fromElement(pubsub_elt)