1 files changed, 1 insertions, 1 deletions
diff --git a/tests/storage/test_event_metrics.py b/tests/storage/test_event_metrics.py
index 6f1135eef4..a91411168c 100644
--- a/tests/storage/test_event_metrics.py
+++ b/tests/storage/test_event_metrics.py
@@ -20,7 +20,7 @@ from tests.unittest import HomeserverTestCase
 
 
 class ExtremStatisticsTestCase(HomeserverTestCase):
-    def test_exposed_to_prometheus(self):
+    def test_exposed_to_prometheus(self) -> None:
         """
         Forward extremity counts are exposed via Prometheus.
         """