diff -u b/core/modules/ckeditor5/js/ckeditor5.dialog.fix.js b/core/modules/ckeditor5/js/ckeditor5.dialog.fix.js
--- b/core/modules/ckeditor5/js/ckeditor5.dialog.fix.js
+++ b/core/modules/ckeditor5/js/ckeditor5.dialog.fix.js
@@ -12,7 +12,10 @@
     // CKEditor 5 in modals can work as expected.
     // @see https://api.jqueryui.com/dialog/#method-_allowInteraction
     _allowInteraction(event) {
-      return event.target.classList && event.target.classList.contains('ck') || this._super(event);
+      return (
+        (event.target.classList && event.target.classList.contains('ck')) ||
+        this._super(event)
+      );
     },
   });
 })(jQuery);