diff --git a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
index 05f88849..f84c21ce 100644
--- a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
+++ b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
@@ -167,6 +167,8 @@ where
 		.collect()
 		.await;
 
+	if extremities.len() == 0 { info!("Retained zero extremities when upgrading outlier PDU to timeline PDU with {} previous events, event id: {}", incoming_pdu.prev_events.len(), incoming_pdu.event_id) }
+	
 	debug!(
 		"Retained {} extremities checked against {} prev_events",
 		extremities.len(),