1 files changed, 5 insertions, 2 deletions
diff --git a/synapse/replication/slave/storage/_base.py b/synapse/replication/slave/storage/_base.py
index e460dd85cd..7ecb446e7c 100644
--- a/synapse/replication/slave/storage/_base.py
+++ b/synapse/replication/slave/storage/_base.py
@@ -13,18 +13,21 @@
 # limitations under the License.
 
 import logging
-from typing import Optional
+from typing import TYPE_CHECKING, Optional
 
 from synapse.storage.database import DatabasePool
 from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore
 from synapse.storage.engines import PostgresEngine
 from synapse.storage.util.id_generators import MultiWriterIdGenerator
 
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
 logger = logging.getLogger(__name__)
 
 
 class BaseSlavedStore(CacheInvalidationWorkerStore):
-    def __init__(self, database: DatabasePool, db_conn, hs):
+    def __init__(self, database: DatabasePool, db_conn, hs: "HomeServer"):
         super().__init__(database, db_conn, hs)
         if isinstance(self.database_engine, PostgresEngine):
             self._cache_id_gen: Optional[