diff --git a/core/misc/ajax.js b/core/misc/ajax.js
index 02a795e..5bb7398 100644
--- a/core/misc/ajax.js
+++ b/core/misc/ajax.js
@@ -781,7 +781,7 @@ Drupal.ajax.prototype.commands = {
       $submit_buttons.mousedown(function(event) {
         this.form.clk = this;
       });
-      $('.dismiss', Drupal.settings.ajaxForm.body).click(function( event ) {
+      $('.modal-dismiss', Drupal.settings.ajaxForm.body).click(function( event ) {
         event.preventDefault();
         Drupal.settings.ajaxForm.popup.dialog('close');
       })
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 11e64e4..33f7464 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -3342,7 +3342,7 @@ function confirm_form($form, $question, $path, $description = NULL, $yes = NULL,
     '#href' => $options['path'],
     '#attributes' => array(
       'class' => array(
-        'dismiss'
+        'modal-dismiss'
       )
     ),
     '#options' => $options,