diff --git a/lib/backend.py b/lib/backend.py
index 426b39014690ea42a9513213d2ac72861421a670..e46649bc0165c0693f1714ec8bce2cc498c1960e 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -98,7 +98,7 @@ def GetMasterInfo():
     master_node = cfg.GetMasterNode()
   except errors.ConfigurationError, err:
     logging.exception("Cluster configuration incomplete")
-    return (None, None)
+    return (None, None, None)
   return (master_netdev, master_ip, master_node)