diff -u b/core/misc/ajax.js b/core/misc/ajax.js
--- b/core/misc/ajax.js
+++ b/core/misc/ajax.js
@@ -1034,10 +1034,10 @@
 
       var $responseDataWrapped = $('<div></div>').html(response.data);
       var $new_content = $('<div></div>');
-      var elementsReturned = $responseDataWrapped.contents().length;
+      var elementsReturnedCount = $responseDataWrapped.contents().length;
 
       // If only one node element is returned skip wrap processing.
-      if (elementsReturned === 1 && response.data === Node.ELEMENT_NODE) {
+      if (elementsReturnedCount === 1 && response.data === Node.ELEMENT_NODE) {
         $new_content = response.data;
       }
       else {
@@ -1067,7 +1067,7 @@
 
           // There are no other elements to process anymore, so add the
           // intermediate wrapper to the content if present.
-          if (index === elementsReturned - 1 && $intermediateWrapper) {
+          if (index === elementsReturnedCount - 1 && $intermediateWrapper) {
             $new_content.append($intermediateWrapper);
           }
         });
@@ -1114,10 +1114,15 @@
       if ($new_content.parents('html').length > 0) {
         // Apply any settings from the returned JSON if available.
         settings = response.settings || ajax.settings || drupalSettings;
-        // Attach behaviors to all element nodes.
-        $wrapper.children().each(function () {
-          Drupal.attachBehaviors(this, settings);
-        });
+        if (method === 'replaceWith') {
+          Drupal.attachBehaviors($wrapper.get(0), settings);
+        }
+        else {
+          // Attach behaviors to all element nodes.
+          $wrapper.children().each(function () {
+            Drupal.attachBehaviors(this, settings);
+          });
+        }
       }
     },