diff --git a/core/lib/Drupal/Core/Render/Element/Table.php b/core/lib/Drupal/Core/Render/Element/Table.php
index c6c08b1..57892d4 100644
--- a/core/lib/Drupal/Core/Render/Element/Table.php
+++ b/core/lib/Drupal/Core/Render/Element/Table.php
@@ -338,7 +338,7 @@ class Table extends FormElement {
    * @see drupal_attach_tabledrag()
    */
   public static function preRenderTable($element) {
-    foreach (Element::children($element) as $first) {
+    foreach (Element::children($element, TRUE) as $first) {
       $row = ['data' => []];
       // Apply attributes of first-level elements as table row attributes.
       if (isset($element[$first]['#attributes'])) {
@@ -347,7 +347,7 @@ class Table extends FormElement {
       // Turn second-level elements into table row columns.
       // @todo Do not render a cell for children of #type 'value'.
       // @see https://www.drupal.org/node/1248940
-      foreach (Element::children($element[$first]) as $second) {
+      foreach (Element::children($element[$first], TRUE) as $second) {
         // Assign the element by reference, so any potential changes to the
         // original element are taken over.
         $column = ['data' => &$element[$first][$second]];