diff -u b/core/misc/ajax.js b/core/misc/ajax.js
--- b/core/misc/ajax.js
+++ b/core/misc/ajax.js
@@ -919,9 +919,11 @@
       // If removing content from the wrapper, detach behaviors first.
       switch (method) {
       // top-level element, and only use the container DIV created above when
-      // it doesn't. For more information, please see http://drupal.org/node/736066.
+      // it doesn't. For more information, please see
+      // https://www.drupal.org/node/736066.
       if ($new_content.length !== 1 || $new_content.get(0).nodeType !== 1) {
         $new_content = $new_content_wrapped;
+      }
 
       // If removing content from the wrapper, detach behaviors first.
 
@@ -956,7 +958,7 @@
       // Attach all JavaScript behaviors to the new content, if it was
       // successfully added to the page, this if statement allows
       // `#ajax['wrapper']` to be optional.
-      if (new_content.parents('html').length > 0) {
+      if ($new_content.parents('html').length > 0) {
         // Apply any settings from the returned JSON if available.
         settings = response.settings || ajax.settings || drupalSettings;
         Drupal.attachBehaviors($new_content.get(0), settings);
@@ -990,10 +992,11 @@
      * @param {number} [status]
      */
     changed: function (ajax, response, status) {
-      if (!$(response.selector).hasClass('ajax-changed')) {
-        $(response.selector).addClass('ajax-changed');
+      var $element = $(response.selector);
+      if (!$element.hasClass('ajax-changed')) {
+        $element.addClass('ajax-changed');
         if (response.asterisk) {
-          $(response.selector).find(response.asterisk).append(' <abbr class="ajax-changed" title="' + Drupal.t('Changed') + '">*</abbr> ');
+          $element.find(response.asterisk).append(' <abbr class="ajax-changed" title="' + Drupal.t('Changed') + '">*</abbr> ');
         }
       }
     },