1 files changed, 4 insertions, 3 deletions
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 8d9086ecf0..596275c23c 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -24,6 +24,7 @@ from typing import (
     Iterable,
     List,
     Optional,
+    Sequence,
     Set,
     Tuple,
 )
@@ -494,7 +495,7 @@ class PersistEventsStore:
         event_chain_id_gen: SequenceGenerator,
         event_to_room_id: Dict[str, str],
         event_to_types: Dict[str, Tuple[str, str]],
-        event_to_auth_chain: Dict[str, List[str]],
+        event_to_auth_chain: Dict[str, Sequence[str]],
     ) -> None:
         """Calculate the chain cover index for the given events.
 
@@ -786,7 +787,7 @@ class PersistEventsStore:
         event_chain_id_gen: SequenceGenerator,
         event_to_room_id: Dict[str, str],
         event_to_types: Dict[str, Tuple[str, str]],
-        event_to_auth_chain: Dict[str, List[str]],
+        event_to_auth_chain: Dict[str, Sequence[str]],
         events_to_calc_chain_id_for: Set[str],
         chain_map: Dict[str, Tuple[int, int]],
     ) -> Dict[str, Tuple[int, int]]:
@@ -1794,7 +1795,7 @@ class PersistEventsStore:
         )
 
         # Insert an edge for every prev_event connection
-        for prev_event_id in event.prev_events:
+        for prev_event_id in event.prev_event_ids():
             self.db_pool.simple_insert_txn(
                 txn,
                 table="insertion_event_edges",