diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index d513c01b7e..ed41dfc7ee 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -533,7 +533,7 @@ class TransportLayerClient(object):
 
     def update_room_group_association(self, destination, group_id, requester_user_id,
                                       room_id, content):
-        """Add a room to a group
+        """Add or update an association between room and group
         """
         path = PREFIX + "/groups/%s/room/%s" % (group_id, room_id,)
 
diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index 69831eacbd..e21ac8e49e 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -533,7 +533,7 @@ class GroupsServerHandler(object):
     @defer.inlineCallbacks
     def update_room_group_association(self, group_id, requester_user_id, room_id,
                                       content):
-        """Add room to group
+        """Add or update an association between room and group
         """
         RoomID.from_string(room_id)  # Ensure valid room id