diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 3c27428c0..5d5b5f7c4 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -44,7 +44,6 @@ class DataStore(RoomDataStore, RoomMemberStore, MessageStore, RoomStore,
     def __init__(self, hs):
         super(DataStore, self).__init__(hs)
         self.event_factory = hs.get_event_factory()
-        self.hs = hs
 
     def persist_event(self, event):
         if event.type == MessageEvent.TYPE:
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 65f691ead..1b98bdfce 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -27,6 +27,7 @@ logger = logging.getLogger(__name__)
 class SQLBaseStore(object):
 
     def __init__(self, hs):
+        self.hs = hs
         self._db_pool = hs.get_db_pool()
 
     def cursor_to_dict(self, cursor):