diff --git a/tests/app/notify_client/test_service_api_client.py b/tests/app/notify_client/test_service_api_client.py
index d7ca81e3a..4a2ef83b8 100644
--- a/tests/app/notify_client/test_service_api_client.py
+++ b/tests/app/notify_client/test_service_api_client.py
@@ -550,5 +550,5 @@ def test_client_deletes_service_template_cache_when_service_is_updated(
     templates_to_delete = mock_redis_delete.call_args_list[0][0]
     assert len(templates_to_delete) == 6
     for template_key in templates_to_delete:
-        assert template_key.startswith('service-{}-template'.format(SERVICE_ONE_ID))
+        assert template_key.startswith(f'service-{SERVICE_ONE_ID}-template')
         assert template_key.endswith('version-None')