diff --git a/core/modules/system/src/Tests/Form/ElementTest.php b/core/modules/system/src/Tests/Form/ElementTest.php
index 5247771..cf3e16e 100644
--- a/core/modules/system/src/Tests/Form/ElementTest.php
+++ b/core/modules/system/src/Tests/Form/ElementTest.php
@@ -102,6 +102,9 @@ function testRadiosChecked() {
     $elements = $this->xpath('//input[@name="radios" and @checked]');
     $this->assertEqual(count($elements), 1);
     $this->assertIdentical((string) $elements[0]['value'], '0');
+    $elements = $this->xpath('//input[@name="radios-string" and @checked]');
+    $this->assertEqual(count($elements), 1);
+    $this->assertIdentical((string) $elements[0]['value'], 'bar');
   }
 
   /**
diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestRadiosCheckedForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestRadiosCheckedForm.php
index 39b7b41..7be930b 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestRadiosCheckedForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestRadiosCheckedForm.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\form_test\Form\FormTestCheckboxesRadiosForm.
+ * Contains \Drupal\form_test\Form\FormTestRadiosCheckedForm.
  */
 
 namespace Drupal\form_test\Form;
@@ -12,7 +12,7 @@
 use Symfony\Component\HttpFoundation\JsonResponse;
 
 /**
- * Form constructor to test expansion of #type checkboxes and radios.
+ * Form constructor to test #default_value settings of radios.
  */
 class FormTestRadiosCheckedForm extends FormBase {
 
@@ -39,6 +39,18 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       ),
       '#default_value' => 0
     );
+    $form['radios-string'] = array(
+      '#type' => 'radios',
+      '#title' => 'Radios',
+      '#options' => array(
+        0 => 'Zero',
+        'foo' => 'Foo',
+        1 => 'One',
+        'bar' => '<em>Bar - radios</em>',
+        '>' => "<em>Special Char</em><script>alert('radios');</script>",
+      ),
+      '#default_value' => 'bar',
+    );
 
     $form['submit'] = array('#type' => 'submit', '#value' => 'Submit');