diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestMachineNameValidationForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestMachineNameValidationForm.php
index 235a8b0..37b13fd 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestMachineNameValidationForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestMachineNameValidationForm.php
@@ -141,7 +141,7 @@ public function load($machine_name) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
-    drupal_set_message('The form_test_machine_name_validation_form form has been submitted successfully.');
+    $this->messenger->addStatus('The form_test_machine_name_validation_form form has been submitted successfully.');
   }
 
 }