diff --git a/lib/public/Broadcast/Events/IBroadcastEvent.php b/lib/public/Broadcast/Events/IBroadcastEvent.php
index 5fffc10e2af0f..88dbcaa52209b 100644
--- a/lib/public/Broadcast/Events/IBroadcastEvent.php
+++ b/lib/public/Broadcast/Events/IBroadcastEvent.php
@@ -13,6 +13,7 @@
 
 /**
  * @since 18.0.0
+ * @deprecated 35.0.0 Not used
  */
 interface IBroadcastEvent {
 	/**