diff --git a/synapse/storage/data_stores/main/devices.py b/synapse/storage/data_stores/main/devices.py
index b2100bb43a..d2fc8c9794 100644
--- a/synapse/storage/data_stores/main/devices.py
+++ b/synapse/storage/data_stores/main/devices.py
@@ -749,7 +749,7 @@ class DeviceBackgroundUpdateStore(SQLBaseStore):
         KEY_COLS = ["stream_id", "destination", "user_id", "device_id"]
         last_row = progress.get(
             "last_row",
-            {"stream_id": 0, "destination": "", "user_id": "", "device_id": "",},
+            {"stream_id": 0, "destination": "", "user_id": "", "device_id": ""},
         )
 
         def _txn(txn):