diff --git a/modules/simpletest/tests/form.test b/modules/simpletest/tests/form.test
index 2f5a9cd..5aa7e4a 100644
--- a/modules/simpletest/tests/form.test
+++ b/modules/simpletest/tests/form.test
@@ -173,6 +173,8 @@ class FormsTestCase extends DrupalWebTestCase {
     $this->assertNoFieldChecked('edit-radios-bar');
     $this->assertNoFieldChecked('edit-radios-optional-foo');
     $this->assertNoFieldChecked('edit-radios-optional-bar');
+    $this->assertNoFieldChecked('edit-radios-optional-default-value-false-foo');
+    $this->assertNoFieldChecked('edit-radios-optional-default-value-false-bar');
 
     // Submit again with required fields set and verify that there are no
     // error messages.
diff --git a/modules/simpletest/tests/form_test.module b/modules/simpletest/tests/form_test.module
index 43a6cbe..a6b21a4 100644
--- a/modules/simpletest/tests/form_test.module
+++ b/modules/simpletest/tests/form_test.module
@@ -372,6 +372,12 @@ function form_test_validate_required_form($form, &$form_state) {
     '#title' => 'Radios (optional)',
     '#options' => $options,
   );
+  $form['radios_optional_default_value_false'] = array(
+    '#type' => 'radios',
+    '#title' => 'Radios (optional, with a default value of FALSE)',
+    '#options' => $options,
+    '#default_value' => FALSE,
+  );
   $form['actions'] = array('#type' => 'actions');
   $form['actions']['submit'] = array('#type' => 'submit', '#value' => 'Submit');
   return $form;