diff --git a/core/modules/system/tests/modules/test_page_test/src/Controller/TestPageTestController.php b/core/modules/system/tests/modules/test_page_test/src/Controller/TestPageTestController.php
index 76ac189..d6721d6 100644
--- a/core/modules/system/tests/modules/test_page_test/src/Controller/TestPageTestController.php
+++ b/core/modules/system/tests/modules/test_page_test/src/Controller/TestPageTestController.php
@@ -13,10 +13,15 @@
 class TestPageTestController {
 
   /**
-   * @todo Remove test_page_test_page().
+   * Controller method to test front page.
    */
   public function testPage() {
-    return test_page_test_page();
+    $attached['drupalSettings']['test-setting'] = 'azAZ09();.,\\\/-_{}';
+    return [
+      '#title' => t('Test page'),
+      '#markup' => t('Test page text.'),
+      '#attached' => $attached,
+    ];
   }
 
 }