diff --git a/hermes_state.py b/hermes_state.py
index 6e1300f5de4..3702623aac4 100644
--- a/hermes_state.py
+++ b/hermes_state.py
@@ -802,6 +802,8 @@ CREATE INDEX IF NOT EXISTS idx_compression_locks_expires ON compression_locks(ex
 DEFERRED_INDEX_SQL = """
 CREATE INDEX IF NOT EXISTS idx_messages_session_active
     ON messages(session_id, active, timestamp);
+CREATE INDEX IF NOT EXISTS idx_messages_active_null
+    ON messages(active) WHERE active IS NULL;
 CREATE INDEX IF NOT EXISTS idx_sessions_session_key
     ON sessions(session_key, started_at DESC);
 CREATE INDEX IF NOT EXISTS idx_sessions_gateway_peer