diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
index 023b1ce..8944a4c 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
@@ -28,9 +28,8 @@ public function getFormId() {
   public function buildForm(array $form, FormStateInterface $form_state) {
     $form['meta'] = [
       '#type' => 'details',
-      '#title' => 'Group element',
+      '#title' => 'Details element',
       '#open' => TRUE,
-      '#group' => 'container',
     ];
     $form['submit'] = ['#type' => 'submit', '#value' => 'Submit'];
     return $form;