diff --git a/synapse/storage/e2e_room_keys.py b/synapse/storage/e2e_room_keys.py
index d82f223e8..089989fcf 100644
--- a/synapse/storage/e2e_room_keys.py
+++ b/synapse/storage/e2e_room_keys.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 from twisted.internet import defer
+from synapse.api.errors import StoreError
 
 from ._base import SQLBaseStore