diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index 6f4f0c7e90..e97fbeed6c 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -15,7 +15,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Any, Collection, Dict, Iterable, List, Optional, Set, Tuple
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Collection,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Set,
+    Tuple,
+)
 
 from synapse.api import errors
 from synapse.api.constants import EventTypes