diff --git a/core/lib/Drupal/Core/Entity/EntityFormController.php b/core/lib/Drupal/Core/Entity/EntityFormController.php
index 0862184..98001fc 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormController.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormController.php
@@ -249,6 +249,11 @@ protected function actions(array $form, array &$form_state) {
         '#ajax' => array(
           'accepts' => 'application/vnd.drupal-modal',
         ),
+        '#attached' => array(
+          'library' => array(
+            array('system', 'drupal.dialog.ajax'),
+          ),
+        ),
         // No need to validate the form when deleting the entity.
         '#submit' => array(
           array($this, 'delete'),
diff --git a/core/lib/Drupal/Core/Form/ConfirmFormHelper.php b/core/lib/Drupal/Core/Form/ConfirmFormHelper.php
index f2b4f25..a22e131 100644
--- a/core/lib/Drupal/Core/Form/ConfirmFormHelper.php
+++ b/core/lib/Drupal/Core/Form/ConfirmFormHelper.php
@@ -61,6 +61,9 @@ public static function buildCancelLink(ConfirmFormInterface $form, Request $requ
 
     $link['#type'] = 'link';
     $link['#title'] = $form->getCancelText();
+    $link['#attributes'] = array(
+      'class' => array('dialog-cancel'),
+    );
     return $link;
   }
 
diff --git a/core/lib/Drupal/Core/Routing/Enhancer/AjaxEnhancer.php b/core/lib/Drupal/Core/Routing/Enhancer/AjaxEnhancer.php
index 4fcd9ea..7568886 100644
--- a/core/lib/Drupal/Core/Routing/Enhancer/AjaxEnhancer.php
+++ b/core/lib/Drupal/Core/Routing/Enhancer/AjaxEnhancer.php
@@ -19,7 +19,7 @@ class AjaxEnhancer implements RouteEnhancerInterface {
   /**
    * Content negotiation library.
    *
-   * @var \Drupal\CoreContentNegotiation
+   * @var \Drupal\Core\ContentNegotiation
    */
   protected $negotiation;
 
diff --git a/core/modules/content_translation/lib/Drupal/content_translation/ContentTranslationController.php b/core/modules/content_translation/lib/Drupal/content_translation/ContentTranslationController.php
index 92c9396..3d9a0fe 100644
--- a/core/modules/content_translation/lib/Drupal/content_translation/ContentTranslationController.php
+++ b/core/modules/content_translation/lib/Drupal/content_translation/ContentTranslationController.php
@@ -168,6 +168,11 @@ public function entityFormAlter(array &$form, array &$form_state, EntityInterfac
           '#ajax' => array(
             'accepts' => 'application/vnd.drupal-modal',
           ),
+          '#attached' => array(
+            'library' => array(
+              array('system', 'drupal.dialog.ajax'),
+            ),
+          ),
           '#weight' => $weight,
           '#submit' => array(array($this, 'entityFormDeleteTranslation')),
           '#access' => $this->getTranslationAccess($entity, 'delete'),
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceEditForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceEditForm.php
index 9df7bf7..83cfd7f 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceEditForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceEditForm.php
@@ -158,6 +158,11 @@ public function buildForm(array $form, array &$form_state, FieldInstanceInterfac
       '#ajax' => array(
         'accepts' => 'application/vnd.drupal-modal',
       ),
+      '#attached' => array(
+        'library' => array(
+          array('system', 'drupal.dialog.ajax'),
+        ),
+      ),
       '#submit' => array(array($this, 'delete')),
     );
     return $form;
diff --git a/core/modules/search/lib/Drupal/search/SearchPageListController.php b/core/modules/search/lib/Drupal/search/SearchPageListController.php
index 6f86728..13027df 100644
--- a/core/modules/search/lib/Drupal/search/SearchPageListController.php
+++ b/core/modules/search/lib/Drupal/search/SearchPageListController.php
@@ -166,6 +166,14 @@ public function buildForm(array $form, array &$form_state) {
     $form['status']['wipe'] = array(
       '#type' => 'submit',
       '#value' => $this->t('Re-index site'),
+      '#ajax' => array(
+        'accepts' => 'application/vnd.drupal-modal',
+      ),
+      '#attached' => array(
+        'library' => array(
+          array('system', 'drupal.dialog.ajax'),
+        ),
+      ),
       '#submit' => array(array($this, 'searchAdminReindexSubmit')),
     );
 
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php
index aad2af6..930879a 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php
@@ -347,6 +347,11 @@ public function buildForm(array $form, array &$form_state, VocabularyInterface $
         '#ajax' => array(
           'accepts' => 'application/vnd.drupal-modal',
         ),
+        '#attached' => array(
+          'library' => array(
+            array('system', 'drupal.dialog.ajax'),
+          ),
+        ),
         '#submit' => array(array($this, 'submitReset')),
         '#value' => $this->t('Reset to alphabetical'),
       );