diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py
index 5e340bd03d..18ae8aee29 100644
--- a/synapse/storage/databases/main/state.py
+++ b/synapse/storage/databases/main/state.py
@@ -12,11 +12,10 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
+import collections.abc
import logging
from typing import TYPE_CHECKING, Collection, Dict, Iterable, Optional, Set, Tuple
-from frozendict import frozendict
-
from synapse.api.constants import EventTypes, Membership
from synapse.api.errors import NotFoundError, UnsupportedRoomVersionError
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
@@ -160,7 +159,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
predecessor = create_event.content.get("predecessor", None)
# Ensure the key is a dictionary
- if not isinstance(predecessor, (dict, frozendict)):
+ if not isinstance(predecessor, collections.abc.Mapping):
return None
# The keys must be strings since the data is JSON.
|
