diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index ad937c1721293439f3b8f541ce66c3da4ab910e0..2d95b04e0c1118eb36e472726a334b0dbcfed37e 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -411,8 +411,8 @@ class GroupsServerHandler(object):
                 "name", "short_description", "long_description",
                 "avatar_url", "is_public",
             ]
-            group_description = { key: group[key] for key in cols }
-            group_description["is_openly_joinable"] = group['join_policy'] == "open"
+            group_description = {key: group[key] for key in cols}
+            group_description["is_openly_joinable"] = group["join_policy"] == "open"
 
             defer.returnValue(group_description)
         else: