2 files changed, 2 insertions, 1 deletions
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 1e99c1303c..c11b98d0b7 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -52,7 +52,7 @@ class RegistrationHandler(BaseHandler):
         if urllib.quote(localpart.encode('utf-8')) != localpart:
             raise SynapseError(
                 400,
-                "User ID can only contain characters a-z, 0-9, or '-./'",
+                "User ID can only contain characters a-z, 0-9, or '_-./'",
                 Codes.INVALID_USERNAME
             )
 
diff --git a/synapse/storage/schema/delta/28/event_push_actions.sql b/synapse/storage/schema/delta/28/event_push_actions.sql
index bdf6ae3f24..4d519849df 100644
--- a/synapse/storage/schema/delta/28/event_push_actions.sql
+++ b/synapse/storage/schema/delta/28/event_push_actions.sql
@@ -24,3 +24,4 @@ CREATE TABLE IF NOT EXISTS event_push_actions(
 
 
 CREATE INDEX event_push_actions_room_id_event_id_user_id_profile_tag on event_push_actions(room_id, event_id, user_id, profile_tag);
+CREATE INDEX event_push_actions_room_id_user_id on event_push_actions(room_id, user_id);