diff --git a/core/modules/system/src/Tests/Common/RenderTest.php b/core/modules/system/src/Tests/Common/RenderTest.php
index b137d19..948cc19 100644
--- a/core/modules/system/src/Tests/Common/RenderTest.php
+++ b/core/modules/system/src/Tests/Common/RenderTest.php
@@ -95,6 +95,13 @@ function testDrupalRenderBasics() {
         ),
         'expected' => '',
       ),
+      array(
+        'name' => 'XSS filtered',
+        'value' => array(
+          '#markup' => 'This is <script>alert(\'XSS\')</script> test',
+        ),
+        'expected' => 'This is alert(\'XSS\') test',
+      ),
 
       // Test that #theme and #theme_wrappers can co-exist on an element.
       array(