diff --git a/lib/yui/formchangechecker/formchangechecker.js b/lib/yui/formchangechecker/formchangechecker.js
index 5c46983f195..ea5164d2742 100644
--- a/lib/yui/formchangechecker/formchangechecker.js
+++ b/lib/yui/formchangechecker/formchangechecker.js
@@ -93,7 +93,7 @@ YUI.add('moodle-core-formchangechecker',
          * Set the form changed state to true
          */
         M.core_formchangechecker.set_form_changed = function(e) {
-            if (e.target.hasClass('ignoredirty')) {
+            if (e && e.target && e.target.hasClass('ignoredirty')) {
                 // Don't warn on elements with the ignoredirty class
                 return;
             }