diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index fdaeba7..6cc4de5 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -83,6 +83,12 @@
 const COMMENT_OPEN = 2;
 
 /**
+ * Comments sortings.
+ */
+const COMMENT_SORTING_ASC = 'ASC';
+const COMMENT_SORTING_DESC = 'DESC';
+
+/**
  * Denotes that access is denied for an entity to which a comment field is
  * attached and no {%entity_type}_access function exists.
  *
@@ -738,8 +744,10 @@ function comment_add(EntityInterface $entity, $field_name = 'comment', $pid = NU
  *   The comment display mode; COMMENT_MODE_FLAT or COMMENT_MODE_THREADED.
  * @param int $comments_per_page
  *   The amount of comments to display per page.
+ * @param string $sort
+ *   Sorting order value. Could be ASC or DESC.
  *
- * @return
+ * @return array
  *   An array of the IDs of the comment to be displayed.
  *
  * To display threaded comments in the correct order we keep a 'thread' field
@@ -796,7 +804,7 @@ function comment_add(EntityInterface $entity, $field_name = 'comment', $pid = NU
  * spoil the reverse ordering, "ORDER BY thread ASC" -- here, we do not need
  * to consider the trailing "/" so we use a substring only.
  */
-function comment_get_thread(EntityInterface $entity, $field_name, $mode, $comments_per_page) {
+function comment_get_thread(EntityInterface $entity, $field_name, $mode, $comments_per_page, $sort = COMMENT_SORTING_ASC) {
   $query = db_select('comment', 'c')
     ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   $query->addField('c', 'cid');
@@ -828,14 +836,22 @@ function comment_get_thread(EntityInterface $entity, $field_name, $mode, $commen
     $count_query->condition('c.status', COMMENT_PUBLISHED);
   }
   if ($mode == COMMENT_MODE_FLAT) {
-    $query->orderBy('c.cid', 'ASC');
+    $query->orderBy('c.cid', $sort);
   }
   else {
     // See comment above. Analysis reveals that this doesn't cost too
     // much. It scales much much better than having the whole comment
     // structure.
-    $query->addExpression('SUBSTRING(c.thread, 1, (LENGTH(c.thread) - 1))', 'torder');
-    $query->orderBy('torder', 'ASC');
+    switch ($sort) {
+      case COMMENT_SORTING_DESC:
+        $query->orderBy('c.thread', $sort);
+        break;
+
+      default:
+        $query->addExpression('SUBSTRING(c.thread, 1, (LENGTH(c.thread) - 1))', 'torder');
+        $query->orderBy('torder', $sort);
+        break;
+    }
   }
 
   $query->setCountQuery($count_query);
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php b/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php
index 6f9ad12..facb0ec 100644
--- a/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php
@@ -23,6 +23,7 @@
  *   instance_settings = {
  *     "default_mode" = COMMENT_MODE_THREADED,
  *     "per_page" = 50,
+ *     "sort" = COMMENT_SORTING_ASC,
  *     "form_location" = COMMENT_FORM_BELOW,
  *     "anonymous" = COMMENT_ANONYMOUS_MAYNOT_CONTACT,
  *     "subject" = 1,
@@ -100,6 +101,15 @@ public function instanceSettingsForm(array $form, array &$form_state) {
       '#default_value' => $settings['default_mode'],
       '#description' => t('Show comment replies in a threaded list.'),
     );
+    $element['comment']['sort'] = array(
+      '#type' => 'select',
+      '#title' => t('Sorting order'),
+      '#default_value' => $settings['sort'],
+      '#options' => array(
+        COMMENT_SORTING_ASC  => t('Ascending'),
+        COMMENT_SORTING_DESC => t('Descending'),
+      ),
+    );
     $element['comment']['per_page'] = array(
       '#type' => 'select',
       '#title' => t('Comments per page'),
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/field/formatter/CommentDefaultFormatter.php b/core/modules/comment/lib/Drupal/comment/Plugin/field/formatter/CommentDefaultFormatter.php
index db55970..186d17c 100644
--- a/core/modules/comment/lib/Drupal/comment/Plugin/field/formatter/CommentDefaultFormatter.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/field/formatter/CommentDefaultFormatter.php
@@ -51,7 +51,8 @@ public function viewElements(EntityInterface $entity, $langcode, array $items) {
         // formatter, @see comment_node_update_index().
         $mode = $comment_settings['default_mode'];
         $comments_per_page = $comment_settings['per_page'];
-        if ($cids = comment_get_thread($entity, $field_name, $mode, $comments_per_page)) {
+        $sort = $comment_settings['sort'];
+        if ($cids = comment_get_thread($entity, $field_name, $mode, $comments_per_page, $sort)) {
           $comments = comment_load_multiple($cids);
           comment_prepare_thread($comments);
           $build = comment_view_multiple($comments);