1 files changed, 3 insertions, 1 deletions
diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py
index db3667dc43..0f0e1cd09b 100644
--- a/tests/storage/test_redaction.py
+++ b/tests/storage/test_redaction.py
@@ -237,7 +237,9 @@ class RedactionTestCase(unittest.HomeserverTestCase):
 
             @defer.inlineCallbacks
             def build(self, prev_event_ids):
-                built_event = yield self._base_builder.build(prev_event_ids)
+                built_event = yield defer.ensureDeferred(
+                    self._base_builder.build(prev_event_ids)
+                )
 
                 built_event._event_id = self._event_id
                 built_event._dict["event_id"] = self._event_id