diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 0cbae9429..fedfb92b3 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -109,7 +109,7 @@ class RoomVersions(object):
 
 
 class RoomDisposition(object):
-    STABLE = "stable",
+    STABLE = "stable"
     UNSTABLE = "unstable"