diff --git a/core/modules/text/lib/Drupal/text/Plugin/field/widget/TextareaWithSummaryWidget.php b/core/modules/text/lib/Drupal/text/Plugin/field/widget/TextareaWithSummaryWidget.php
index 6c0e534..6a10b2c 100644
--- a/core/modules/text/lib/Drupal/text/Plugin/field/widget/TextareaWithSummaryWidget.php
+++ b/core/modules/text/lib/Drupal/text/Plugin/field/widget/TextareaWithSummaryWidget.php
@@ -43,7 +43,7 @@ function formElement(array $items, $delta, array $element, $langcode, array &$fo
       '#default_value' => isset($items[$delta]['summary']) ? $items[$delta]['summary'] : NULL,
       '#title' => t('Summary'),
       '#rows' => $this->getSetting('summary_rows'),
-      '#description' => t('Leave blank to use trimmed value of full text as the summary.'),
+      '#description' => empty($this->instance['settings']['required_summary']) ? t('Leave blank to use trimmed value of full text as the summary.') : '',
       '#attached' => array(
         'library' => array(array('text', 'drupal.text')),
       ),
@@ -55,7 +55,7 @@ function formElement(array $items, $delta, array $element, $langcode, array &$fo
     );
 
     if (empty($this->instance['settings']['show_summary'])) {
-      $element['summary']['#attached']['js'] = array(drupal_get_path('module', 'text') . '/text.js');
+      $element['summary']['#attached']['library'] = array(array('text', 'drupal.text'));
     }
 
     return $element;