diff --git a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
index 4794de8f3..5d47d03ad 100644
--- a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
+++ b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
@@ -97,7 +97,7 @@ pub(super) async fn upgrade_outlier_to_timeline_pdu(
 
 	let state_at_incoming_event =
 		state_at_incoming_event.expect("we always set this to some above");
-	assert!(!state_at_incoming_event.is_empty(), "Event has no incoming state");
+	debug_assert!(!state_at_incoming_event.is_empty(), "Event has no incoming state");
 	trace!(state_events = state_at_incoming_event.len(), "Calculated incoming state");
 
 	debug!(