diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py
index e2e48a529..c7ae5c815 100644
--- a/tests/storage/test_redaction.py
+++ b/tests/storage/test_redaction.py
@@ -244,6 +244,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
             def __init__(self, base_builder: EventBuilder, event_id: str):
                 self._base_builder = base_builder
                 self._event_id = event_id
+                self.room_version = base_builder.room_version
 
             async def build(
                 self,