1 files changed, 2 insertions, 0 deletions
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index 7ca5c9940a..5022e0fcb3 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -54,6 +54,8 @@ def prune_event(event: EventBase) -> EventBase:
         event.internal_metadata.stream_ordering
     )
 
+    pruned_event.internal_metadata.outlier = event.internal_metadata.outlier
+
     # Mark the event as redacted
     pruned_event.internal_metadata.redacted = True