diff --git a/synapse/replication/slave/storage/_base.py b/synapse/replication/slave/storage/_base.py
index b962641166..61f5590c53 100644
--- a/synapse/replication/slave/storage/_base.py
+++ b/synapse/replication/slave/storage/_base.py
@@ -25,7 +25,7 @@ logger = logging.getLogger(__name__)
 
 class BaseSlavedStore(SQLBaseStore):
     def __init__(self, db_conn, hs):
-        super(BaseSlavedStore, self).__init__(hs)
+        super(BaseSlavedStore, self).__init__(db_conn, hs)
         if isinstance(self.database_engine, PostgresEngine):
             self._cache_id_gen = SlavedIdTracker(
                 db_conn, "cache_invalidation_stream", "stream_id",
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 594566eb38..d01d46338a 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -268,7 +268,7 @@ class DataStore(RoomMemberStore, RoomStore,
         self._stream_order_on_start = self.get_room_max_stream_ordering()
         self._min_stream_order_on_start = self.get_room_min_stream_ordering()
 
-        super(DataStore, self).__init__(hs)
+        super(DataStore, self).__init__(db_conn, hs)
 
     def take_presence_startup_info(self):
         active_on_startup = self._presence_on_startup
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 6caf7b3356..e94917d9cd 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -162,7 +162,7 @@ class PerformanceCounters(object):
 class SQLBaseStore(object):
     _TXN_ID = 0
 
-    def __init__(self, hs):
+    def __init__(self, db_conn, hs):
         self.hs = hs
         self._clock = hs.get_clock()
         self._db_pool = hs.get_db_pool()
diff --git a/synapse/storage/appservice.py b/synapse/storage/appservice.py
index c63935cb07..d8c84b7141 100644
--- a/synapse/storage/appservice.py
+++ b/synapse/storage/appservice.py
@@ -48,8 +48,8 @@ def _make_exclusive_regex(services_cache):
 
 class ApplicationServiceStore(SQLBaseStore):
 
-    def __init__(self, hs):
-        super(ApplicationServiceStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(ApplicationServiceStore, self).__init__(db_conn, hs)
         self.hostname = hs.hostname
         self.services_cache = load_appservices(
             hs.hostname,
@@ -173,8 +173,8 @@ class ApplicationServiceStore(SQLBaseStore):
 
 class ApplicationServiceTransactionStore(SQLBaseStore):
 
-    def __init__(self, hs):
-        super(ApplicationServiceTransactionStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(ApplicationServiceTransactionStore, self).__init__(db_conn, hs)
 
     @defer.inlineCallbacks
     def get_appservices_by_state(self, state):
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index a6e6f52a6a..6f235ac051 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -80,8 +80,8 @@ class BackgroundUpdateStore(SQLBaseStore):
     BACKGROUND_UPDATE_INTERVAL_MS = 1000
     BACKGROUND_UPDATE_DURATION_MS = 100
 
-    def __init__(self, hs):
-        super(BackgroundUpdateStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(BackgroundUpdateStore, self).__init__(db_conn, hs)
         self._background_update_performance = {}
         self._background_update_queue = []
         self._background_update_handlers = {}
diff --git a/synapse/storage/client_ips.py b/synapse/storage/client_ips.py
index 3c95e90eca..a03d1d6104 100644
--- a/synapse/storage/client_ips.py
+++ b/synapse/storage/client_ips.py
@@ -32,14 +32,14 @@ LAST_SEEN_GRANULARITY = 120 * 1000
 
 
 class ClientIpStore(background_updates.BackgroundUpdateStore):
-    def __init__(self, hs):
+    def __init__(self, db_conn, hs):
         self.client_ip_last_seen = Cache(
             name="client_ip_last_seen",
             keylen=4,
             max_entries=50000 * CACHE_SIZE_FACTOR,
         )
 
-        super(ClientIpStore, self).__init__(hs)
+        super(ClientIpStore, self).__init__(db_conn, hs)
 
         self.register_background_index_update(
             "user_ips_device_index",
diff --git a/synapse/storage/deviceinbox.py b/synapse/storage/deviceinbox.py
index 0b62b493d5..548e795daf 100644
--- a/synapse/storage/deviceinbox.py
+++ b/synapse/storage/deviceinbox.py
@@ -29,8 +29,8 @@ logger = logging.getLogger(__name__)
 class DeviceInboxStore(BackgroundUpdateStore):
     DEVICE_INBOX_STREAM_ID = "device_inbox_stream_drop"
 
-    def __init__(self, hs):
-        super(DeviceInboxStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(DeviceInboxStore, self).__init__(db_conn, hs)
 
         self.register_background_index_update(
             "device_inbox_stream_index",
diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index bb27fd1f70..bd2effdf34 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -26,8 +26,8 @@ logger = logging.getLogger(__name__)
 
 
 class DeviceStore(SQLBaseStore):
-    def __init__(self, hs):
-        super(DeviceStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(DeviceStore, self).__init__(db_conn, hs)
 
         # Map of (user_id, device_id) -> bool. If there is an entry that implies
         # the device exists.
diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py
index e8133de2fa..55a05c59d5 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/event_federation.py
@@ -39,8 +39,8 @@ class EventFederationStore(SQLBaseStore):
 
     EVENT_AUTH_STATE_ONLY = "event_auth_state_only"
 
-    def __init__(self, hs):
-        super(EventFederationStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(EventFederationStore, self).__init__(db_conn, hs)
 
         self.register_background_update_handler(
             self.EVENT_AUTH_STATE_ONLY,
diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/event_push_actions.py
index d6d8723b4a..8efe2fd4bb 100644
--- a/synapse/storage/event_push_actions.py
+++ b/synapse/storage/event_push_actions.py
@@ -65,8 +65,8 @@ def _deserialize_action(actions, is_highlight):
 class EventPushActionsStore(SQLBaseStore):
     EPA_HIGHLIGHT_INDEX = "epa_highlight_index"
 
-    def __init__(self, hs):
-        super(EventPushActionsStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(EventPushActionsStore, self).__init__(db_conn, hs)
 
         self.register_background_index_update(
             self.EPA_HIGHLIGHT_INDEX,
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 4298d8baf1..d08f7571d7 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -197,8 +197,8 @@ class EventsStore(SQLBaseStore):
     EVENT_ORIGIN_SERVER_TS_NAME = "event_origin_server_ts"
     EVENT_FIELDS_SENDER_URL_UPDATE_NAME = "event_fields_sender_url"
 
-    def __init__(self, hs):
-        super(EventsStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(EventsStore, self).__init__(db_conn, hs)
         self._clock = hs.get_clock()
         self.register_background_update_handler(
             self.EVENT_ORIGIN_SERVER_TS_NAME, self._background_reindex_origin_server_ts
diff --git a/synapse/storage/receipts.py b/synapse/storage/receipts.py
index f42b8014c7..12b3cc7f5f 100644
--- a/synapse/storage/receipts.py
+++ b/synapse/storage/receipts.py
@@ -27,8 +27,8 @@ logger = logging.getLogger(__name__)
 
 
 class ReceiptsStore(SQLBaseStore):
-    def __init__(self, hs):
-        super(ReceiptsStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(ReceiptsStore, self).__init__(db_conn, hs)
 
         self._receipts_stream_cache = StreamChangeCache(
             "ReceiptsRoomChangeCache", self._receipts_id_gen.get_current_token()
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 71748de733..8b9544c209 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -24,8 +24,8 @@ from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
 
 class RegistrationStore(background_updates.BackgroundUpdateStore):
 
-    def __init__(self, hs):
-        super(RegistrationStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(RegistrationStore, self).__init__(db_conn, hs)
 
         self.clock = hs.get_clock()
 
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index 3fa8019eb7..3e77fd3901 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -49,8 +49,8 @@ _MEMBERSHIP_PROFILE_UPDATE_NAME = "room_membership_profile_update"
 
 
 class RoomMemberStore(SQLBaseStore):
-    def __init__(self, hs):
-        super(RoomMemberStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(RoomMemberStore, self).__init__(db_conn, hs)
         self.register_background_update_handler(
             _MEMBERSHIP_PROFILE_UPDATE_NAME, self._background_add_membership_profile
         )
diff --git a/synapse/storage/search.py b/synapse/storage/search.py
index 05d4ef586e..479b04c636 100644
--- a/synapse/storage/search.py
+++ b/synapse/storage/search.py
@@ -33,8 +33,8 @@ class SearchStore(BackgroundUpdateStore):
     EVENT_SEARCH_ORDER_UPDATE_NAME = "event_search_order"
     EVENT_SEARCH_USE_GIST_POSTGRES_NAME = "event_search_postgres_gist"
 
-    def __init__(self, hs):
-        super(SearchStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(SearchStore, self).__init__(db_conn, hs)
         self.register_background_update_handler(
             self.EVENT_SEARCH_UPDATE_NAME, self._background_reindex_search
         )
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 5673e4aa96..dd01b68762 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -63,8 +63,8 @@ class StateStore(SQLBaseStore):
     STATE_GROUP_INDEX_UPDATE_NAME = "state_group_state_type_index"
     CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
 
-    def __init__(self, hs):
-        super(StateStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(StateStore, self).__init__(db_conn, hs)
         self.register_background_update_handler(
             self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME,
             self._background_deduplicate_state,
diff --git a/synapse/storage/transactions.py b/synapse/storage/transactions.py
index 809fdd311f..8f61f7ffae 100644
--- a/synapse/storage/transactions.py
+++ b/synapse/storage/transactions.py
@@ -46,8 +46,8 @@ class TransactionStore(SQLBaseStore):
     """A collection of queries for handling PDUs.
     """
 
-    def __init__(self, hs):
-        super(TransactionStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(TransactionStore, self).__init__(db_conn, hs)
 
         self._clock.looping_call(self._cleanup_transactions, 30 * 60 * 1000)
 
diff --git a/tests/storage/test_appservice.py b/tests/storage/test_appservice.py
index 79f569e787..13d81f972b 100644
--- a/tests/storage/test_appservice.py
+++ b/tests/storage/test_appservice.py
@@ -58,7 +58,7 @@ class ApplicationServiceStoreTestCase(unittest.TestCase):
         self._add_appservice("token2", "as2", "some_url", "some_hs_token", "bob")
         self._add_appservice("token3", "as3", "some_url", "some_hs_token", "bob")
         # must be done after inserts
-        self.store = ApplicationServiceStore(hs)
+        self.store = ApplicationServiceStore(None, hs)
 
     def tearDown(self):
         # TODO: suboptimal that we need to create files for tests!
@@ -150,7 +150,7 @@ class ApplicationServiceTransactionStoreTestCase(unittest.TestCase):
 
         self.as_yaml_files = []
 
-        self.store = TestTransactionStore(hs)
+        self.store = TestTransactionStore(None, hs)
 
     def _add_service(self, url, as_token, id):
         as_yaml = dict(url=url, as_token=as_token, hs_token="something",
@@ -420,8 +420,8 @@ class ApplicationServiceTransactionStoreTestCase(unittest.TestCase):
 class TestTransactionStore(ApplicationServiceTransactionStore,
                            ApplicationServiceStore):
 
-    def __init__(self, hs):
-        super(TestTransactionStore, self).__init__(hs)
+    def __init__(self, db_conn, hs):
+        super(TestTransactionStore, self).__init__(db_conn, hs)
 
 
 class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
@@ -458,7 +458,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
             replication_layer=Mock(),
         )
 
-        ApplicationServiceStore(hs)
+        ApplicationServiceStore(None, hs)
 
     @defer.inlineCallbacks
     def test_duplicate_ids(self):
@@ -477,7 +477,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
         )
 
         with self.assertRaises(ConfigError) as cm:
-            ApplicationServiceStore(hs)
+            ApplicationServiceStore(None, hs)
 
         e = cm.exception
         self.assertIn(f1, e.message)
@@ -501,7 +501,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
         )
 
         with self.assertRaises(ConfigError) as cm:
-            ApplicationServiceStore(hs)
+            ApplicationServiceStore(None, hs)
 
         e = cm.exception
         self.assertIn(f1, e.message)
diff --git a/tests/storage/test_base.py b/tests/storage/test_base.py
index 91e971190c..0ac910e76f 100644
--- a/tests/storage/test_base.py
+++ b/tests/storage/test_base.py
@@ -56,7 +56,7 @@ class SQLBaseStoreTestCase(unittest.TestCase):
             database_engine=create_engine(config.database_config),
         )
 
-        self.datastore = SQLBaseStore(hs)
+        self.datastore = SQLBaseStore(None, hs)
 
     @defer.inlineCallbacks
     def test_insert_1col(self):
diff --git a/tests/storage/test_directory.py b/tests/storage/test_directory.py
index b087892e0b..95709cd50a 100644
--- a/tests/storage/test_directory.py
+++ b/tests/storage/test_directory.py
@@ -29,7 +29,7 @@ class DirectoryStoreTestCase(unittest.TestCase):
     def setUp(self):
         hs = yield setup_test_homeserver()
 
-        self.store = DirectoryStore(hs)
+        self.store = DirectoryStore(None, hs)
 
         self.room = RoomID.from_string("!abcde:test")
         self.alias = RoomAlias.from_string("#my-room:test")
diff --git a/tests/storage/test_presence.py b/tests/storage/test_presence.py
index 63203cea35..f5fcb611d4 100644
--- a/tests/storage/test_presence.py
+++ b/tests/storage/test_presence.py
@@ -29,7 +29,7 @@ class PresenceStoreTestCase(unittest.TestCase):
     def setUp(self):
         hs = yield setup_test_homeserver(clock=MockClock())
 
-        self.store = PresenceStore(hs)
+        self.store = PresenceStore(None, hs)
 
         self.u_apple = UserID.from_string("@apple:test")
         self.u_banana = UserID.from_string("@banana:test")
diff --git a/tests/storage/test_profile.py b/tests/storage/test_profile.py
index 24118bbc86..423710c9c1 100644
--- a/tests/storage/test_profile.py
+++ b/tests/storage/test_profile.py
@@ -29,7 +29,7 @@ class ProfileStoreTestCase(unittest.TestCase):
     def setUp(self):
         hs = yield setup_test_homeserver()
 
-        self.store = ProfileStore(hs)
+        self.store = ProfileStore(None, hs)
 
         self.u_frank = UserID.from_string("@frank:test")