diff --git a/src/conversejs/converse.js b/src/conversejs/converse.js
index 1b3d70d383c57699cf9b06fd476c1306a9f3590b..027a314296898e99686e1ebbfcbb003c2278e767 100644
--- a/src/conversejs/converse.js
+++ b/src/conversejs/converse.js
@@ -98545,7 +98545,7 @@ const ChatBoxView = View.extend({
        * @example _converse.api.listen.on('chatBoxScrolledUp', obj => { ... });
        */
       core_api.trigger('chatBoxScrolledUp', this);
-    } else {
+    } else if (ev.target) {
       scrollTop = ev.target.scrollTop;
     }