diff -u b/core/lib/Drupal/Core/Render/Element/Table.php b/core/lib/Drupal/Core/Render/Element/Table.php
--- b/core/lib/Drupal/Core/Render/Element/Table.php
+++ b/core/lib/Drupal/Core/Render/Element/Table.php
@@ -134,7 +134,7 @@
         // an #id for the row element, since
         // \Drupal\Component\Utility\Html::getUniqueId() would automatically
         // append a suffix to the tableselect form element's #id otherwise.
-        $row['#id'] = Html::getUniqueId('edit-' . implode('-', $element_parents) . '-row');
+        $row['#id'] = \Drupal\Component\Utility\Html::getUniqueId('edit-' . implode('-', $element_parents) . '-row');
 
         // Do not overwrite manually created children.
         if (!isset($row['select'])) {