diff --git a/core/includes/form.inc b/core/includes/form.inc
index 5deb493..098ab8d 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -1596,52 +1596,50 @@ function form_process_container($element, &$form_state) {
 }
 
 /**
- * Returns HTML for a table with radio buttons or checkboxes.
+ * Prepares a 'tableselect' #type element for rendering.
  *
- * @param $variables
- *   An associative array containing:
- *   - element: An associative array containing the properties and children of
- *     the tableselect element. Properties used: #header, #options, #empty,
- *     and #js_select. The #options property is an array of selection options;
- *     each array element of #options is an array of properties. These
- *     properties can include #attributes, which is added to the
- *     table row's HTML attributes; see theme_table(). An example of per-row
- *     options:
- *     @code
- *     $options = array(
- *       array(
- *         'title' => 'How to Learn Drupal',
- *         'content_type' => 'Article',
- *         'status' => 'published',
- *         '#attributes' => array('class' => array('article-row')),
- *       ),
- *       array(
- *         'title' => 'Privacy Policy',
- *         'content_type' => 'Page',
- *         'status' => 'published',
- *         '#attributes' => array('class' => array('page-row')),
- *       ),
- *     );
- *     $header = array(
- *       'title' => t('Title'),
- *       'content_type' => t('Content type'),
- *       'status' => t('Status'),
- *     );
- *     $form['table'] = array(
- *       '#type' => 'tableselect',
- *       '#header' => $header,
- *       '#options' => $options,
- *       '#empty' => t('No content available.'),
- *     );
- *     @endcode
+ * Adds a column of radio buttons or checkboxes for each row of a table.
  *
- * @ingroup themeable
+ * @param array $element
+ *   An associative array containing the properties and children of
+ *   the tableselect element. Properties used: #header, #options, #empty,
+ *   and #js_select. The #options property is an array of selection options;
+ *   each array element of #options is an array of properties. These
+ *   properties can include #attributes, which is added to the
+ *   table row's HTML attributes; see theme_table(). An example of per-row
+ *   options:
+ * @code
+ * $options = array(
+ *   array(
+ *     'title' => 'How to Learn Drupal',
+ *     'content_type' => 'Article',
+ *     'status' => 'published',
+ *     '#attributes' => array('class' => array('article-row')),
+ *   ),
+ *   array(
+ *     'title' => 'Privacy Policy',
+ *     'content_type' => 'Page',
+ *     'status' => 'published',
+ *     '#attributes' => array('class' => array('page-row')),
+ *   ),
+ * );
+ * $header = array(
+ *   'title' => t('Title'),
+ *   'content_type' => t('Content type'),
+ *   'status' => t('Status'),
+ * );
+ * $form['table'] = array(
+ *   '#type' => 'tableselect',
+ *   '#header' => $header,
+ *   '#options' => $options,
+ *   '#empty' => t('No content available.'),
+ * );
+ * @endcode
+ *
+ * @return array
+ *   The processed element.
  */
-function theme_tableselect($variables) {
-  $element = $variables['element'];
-  $table = array(
-    '#type' => 'table',
-  );
+function form_pre_render_tableselect($element) {
   $rows = array();
   $header = $element['#header'];
   if (!empty($element['#options'])) {
@@ -1681,7 +1679,7 @@ function theme_tableselect($variables) {
     // checkboxes/radios in the first table column.
     if ($element['#js_select']) {
       // Add a "Select all" checkbox.
-      $table['#attached']['library'][] = 'core/drupal.tableselect';
+      $element['#attached']['library'][] = 'core/drupal.tableselect';
       array_unshift($header, array('class' => array('select-all')));
     }
     else {
@@ -1690,24 +1688,21 @@ function theme_tableselect($variables) {
       array_unshift($header, '');
     }
   }
-  $table += array(
-    '#header' => $header,
-    '#rows' => $rows,
-    '#empty' => $element['#empty'],
-    '#attributes' => $element['#attributes'],
-  );
 
-  return drupal_render($table);
+  $element['#header'] = $header;
+  $element['#rows'] = $rows;
+
+  return $element;
 }
 
 /**
  * Creates checkbox or radio elements to populate a tableselect table.
  *
- * @param $element
+ * @param array $element
  *   An associative array containing the properties and children of the
  *   tableselect element.
  *
- * @return
+ * @return array
  *   The processed element.
  */
 function form_process_tableselect($element) {
@@ -1789,7 +1784,6 @@ function form_process_tableselect($element) {
  *   The processed element.
  *
  * @see form_process_tableselect()
- * @see theme_tableselect()
  */
 function form_process_table($element, &$form_state) {
   if ($element['#tableselect']) {
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index fbcc619..db4583f 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2659,9 +2659,6 @@ function drupal_common_theme() {
       'render element' => 'element',
       'template' => 'textarea',
     ),
-    'tableselect' => array(
-      'render element' => 'element',
-    ),
     'form_element' => array(
       'render element' => 'element',
       'template' => 'form-element',
diff --git a/core/modules/comment/src/Form/CommentAdminOverview.php b/core/modules/comment/src/Form/CommentAdminOverview.php
index efcd19e..ab6ab97 100644
--- a/core/modules/comment/src/Form/CommentAdminOverview.php
+++ b/core/modules/comment/src/Form/CommentAdminOverview.php
@@ -202,15 +202,22 @@ public function buildForm(array $form, array &$form_state, $type = 'new') {
             '#title' => $comment->getSubject(),
           ) + $comment_permalink->toRenderArray(),
         ),
-        'author' => drupal_render($username),
+        'author' => array(
+          'data' => $username,
+          'class' => array(RESPONSIVE_PRIORITY_MEDIUM),
+        ),
         'posted_in' => array(
           'data' => array(
             '#type' => 'link',
             '#title' => $commented_entity->label(),
             '#access' => $commented_entity->access('view'),
           ) + $commented_entity->urlInfo()->toRenderArray(),
+          'class' => array(RESPONSIVE_PRIORITY_LOW),
+        ),
+        'changed' => array(
+          'data' => $this->date->format($comment->getChangedTime(), 'short'),
+          'class' => array(RESPONSIVE_PRIORITY_LOW),
         ),
-        'changed' => $this->date->format($comment->getChangedTime(), 'short'),
       );
       $comment_uri_options = $comment->urlInfo()->getOptions();
       $links = array();
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 7fbfd99..41cf3b8 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -541,10 +541,13 @@ function system_element_info() {
     '#input' => TRUE,
     '#js_select' => TRUE,
     '#multiple' => TRUE,
+    '#responsive' => TRUE,
+    '#sticky' => FALSE,
+    '#pre_render' => array('drupal_pre_render_table','form_pre_render_tableselect'),
     '#process' => array('form_process_tableselect'),
     '#options' => array(),
     '#empty' => '',
-    '#theme' => 'tableselect',
+    '#theme' => 'table__tableselect',
   );
 
   // Form structure.