diff --git a/core/lib/Drupal/Core/Render/Element/RenderElement.php b/core/lib/Drupal/Core/Render/Element/RenderElement.php
index 4968aaf..f7ad74b 100644
--- a/core/lib/Drupal/Core/Render/Element/RenderElement.php
+++ b/core/lib/Drupal/Core/Render/Element/RenderElement.php
@@ -161,7 +161,7 @@ public static function preRenderAjaxForm($element) {
     $element['#ajax_processed'] = FALSE;
 
     // Nothing to do if there are no Ajax settings.
-    if (empty($element['#ajax'])) {
+    if (!isset($element['#ajax'])) {
       return $element;
     }
 
diff --git a/core/modules/views/src/Plugin/views/field/Field.php b/core/modules/views/src/Plugin/views/field/Field.php
index 386456c..a2b64ee 100644
--- a/core/modules/views/src/Plugin/views/field/Field.php
+++ b/core/modules/views/src/Plugin/views/field/Field.php
@@ -448,7 +448,6 @@ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
       '#options' => $formatters,
       '#default_value' => $this->options['type'],
       '#ajax' => array(
-        'url' => views_ui_build_form_url($form_state),
       ),
       '#submit' => array(array($this, 'submitTemporaryForm')),
       '#executes_submit_callback' => TRUE,