Return immutable objects for cachedList decorators (#16350)

1 files changed, 2 insertions, 2 deletions

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py

index 1a4d394eda..7bd42f635f 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -235,7 +235,7 @@ class SyncResult:
     archived: List[ArchivedSyncResult]
     to_device: List[JsonDict]
     device_lists: DeviceListUpdates
-    device_one_time_keys_count: JsonDict
+    device_one_time_keys_count: JsonMapping
     device_unused_fallback_key_types: List[str]
 
     def __bool__(self) -> bool:
@@ -1558,7 +1558,7 @@ class SyncHandler:
 
         logger.debug("Fetching OTK data")
         device_id = sync_config.device_id
-        one_time_keys_count: JsonDict = {}
+        one_time_keys_count: JsonMapping = {}
         unused_fallback_key_types: List[str] = []
         if device_id:
             # TODO: We should have a way to let clients differentiate between the states of: