diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestOptionalContainerForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestOptionalContainerForm.php
index 8a6acdc..4f60771 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestOptionalContainerForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestOptionalContainerForm.php
@@ -26,13 +26,11 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'container',
       '#attributes' => ['class' => ['empty_optional']],
       '#optional' => TRUE,
-      'child' => ['#markup' => ''],
     ];
     $form['empty_nonoptional'] = [
       '#type' => 'container',
       '#attributes' => ['class' => ['empty_nonoptional']],
       '#optional' => FALSE,
-      'child' => ['#markup' => ''],
     ];
 
     // Non-empty containers
@@ -40,13 +38,13 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'container',
       '#attributes' => ['class' => ['nonempty_optional']],
       '#optional' => TRUE,
-      'child' => ['#markup' => '<b>nonempty_optional value</b>'],
+      'child' => [],
     ];
     $form['nonempty_nonoptional'] = [
       '#type' => 'container',
       '#attributes' => ['class' => ['nonempty_nonoptional']],
       '#optional' => FALSE,
-      'child' => ['#markup' => '<b>nonempty_nonoptional value</b>'],
+      'child' => [],
     ];
 
     return $form;