diff --git a/core/lib/Drupal/Core/Render/Element/MachineName.php b/core/lib/Drupal/Core/Render/Element/MachineName.php
index 9259367..8b9c840 100644
--- a/core/lib/Drupal/Core/Render/Element/MachineName.php
+++ b/core/lib/Drupal/Core/Render/Element/MachineName.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Language\LanguageInterface;
-use Drupal\Core\Logger\RfcLogLevel;
 
 /**
  * Provides a machine name render element.
@@ -258,7 +257,7 @@ public static function validateMachineName(&$element, FormStateInterface $form_s
    *   Whether to set a property on form state in case of an error to revalidate
    *   the element again on the next submission.
    */
-  protected function isUnique($element, FormStateInterface $form_state, $set_needs_revalidation = TRUE) {
+  public static function isUnique($element, FormStateInterface $form_state, $set_needs_revalidation = TRUE) {
     $function = $element['#machine_name']['exists'];
     if (call_user_func($function, $element['#value'], $element, $form_state)) {
       if ($set_needs_revalidation) {