diff --git a/core/modules/rest/tests/src/Unit/CollectRoutesTest.php b/core/modules/rest/tests/src/Unit/CollectRoutesTest.php
index 7a2cbae..c49ff87 100644
--- a/core/modules/rest/tests/src/Unit/CollectRoutesTest.php
+++ b/core/modules/rest/tests/src/Unit/CollectRoutesTest.php
@@ -76,6 +76,7 @@ protected function setUp() {
       ->disableOriginalConstructor()
       ->getMock();
     $container->set('plugin.manager.views.style', $style_manager);
+    $container->set('renderer', $this->getMock('Drupal\Core\Render\RendererInterface'));
 
     \Drupal::setContainer($container);