diff --git a/lib/galaxy/managers/configuration.py b/lib/galaxy/managers/configuration.py
index e6fe7cad9ab..b5bacc890b7 100644
--- a/lib/galaxy/managers/configuration.py
+++ b/lib/galaxy/managers/configuration.py
@@ -55,6 +55,7 @@ class ConfigSerializer( base.ModelSerializer ):
 
             'communication_server_host' : _defaults_to( None ),
             'communication_server_port' : _defaults_to( None ),
+            'persistent_communication_rooms' : _defaults_to( None ),
             'allow_user_creation'       : _defaults_to( False ),
             'use_remote_user'           : _defaults_to( None ),
             'remote_user_logout_href'   : _defaults_to( '' ),