diff --git c/core/modules/system/tests/modules/common_test/common_test.module w/core/modules/system/tests/modules/common_test/common_test.module
index bd44401..0c6cdb6 100644
--- c/core/modules/system/tests/modules/common_test/common_test.module
+++ w/core/modules/system/tests/modules/common_test/common_test.module
@@ -21,12 +21,6 @@ function common_test_menu() {
     'access arguments' => array('access content'),
     'type' => MENU_CALLBACK,
   );
-  $items['common-test/drupal-render-invalid-keys'] = array(
-    'title' => 'Drupal Render',
-    'page callback' => 'common_test_drupal_render_invalid_keys',
-    'access arguments' => array('access content'),
-    'type' => MENU_CALLBACK,
-  );
   return $items;
 }
 
@@ -39,22 +33,6 @@ function common_test_destination() {
 }
 
 /**
- * Renders an element with an invalid render array key.
- */
-function common_test_drupal_render_invalid_keys() {
-  define('SIMPLETEST_COLLECT_ERRORS', FALSE);
-
-  // Keys that begin with # may contain a value of any type, otherwise they must
-  // contain arrays.
-  $key = 'child';
-  $value = 'This should be an array.';
-  $element = array(
-    $key => $value,
-  );
-  return drupal_render($element);
-}
-
-/**
  * Applies #printed to an element to help test #pre_render.
  */
 function common_test_drupal_render_printing_pre_render($elements) {
diff --git c/core/modules/system/tests/modules/common_test/common_test.routing.yml w/core/modules/system/tests/modules/common_test/common_test.routing.yml
index b3186c3..fb27e33 100644
--- c/core/modules/system/tests/modules/common_test/common_test.routing.yml
+++ w/core/modules/system/tests/modules/common_test/common_test.routing.yml
@@ -4,3 +4,10 @@ common_test_l_active_class:
     _content: '\Drupal\common_test\Controller\CommonTestController::typeLinkActiveClass'
   requirements:
     _access: 'TRUE'
+common_test_drupal_render_invalid_keys:
+  pattern: 'common-test/drupal-render-invalid-keys'
+  defaults:
+    _title: 'Drupal Render'
+    _content: '\Drupal\common_test\Controller\CommonTestController::drupalRenderInvalidKeys'
+  requirements:
+    _permission: 'access content'
diff --git c/core/modules/system/tests/modules/common_test/lib/Drupal/common_test/Controller/CommonTestController.php w/core/modules/system/tests/modules/common_test/lib/Drupal/common_test/Controller/CommonTestController.php
index b8e103f..661b37a 100644
--- c/core/modules/system/tests/modules/common_test/lib/Drupal/common_test/Controller/CommonTestController.php
+++ w/core/modules/system/tests/modules/common_test/lib/Drupal/common_test/Controller/CommonTestController.php
@@ -59,4 +59,18 @@ public function typeLinkActiveClass() {
     );
   }
 
+  /**
+   * Renders an element with an invalid render array key.
+   *
+   * @return array
+   *   A render array.
+   */
+  public function drupalRenderInvalidKeys() {
+    define('SIMPLETEST_COLLECT_ERRORS', FALSE);
+    // Keys that begin with # may contain a value of any type, otherwise they must
+    // contain arrays.
+    $element = array('child' => 'This should be an array.');
+    return drupal_render($element);
+  }
+
 }