diff --git a/modules/simpletest/tests/theme.test b/modules/simpletest/tests/theme.test
index f1a743e..c677685 100644
--- a/modules/simpletest/tests/theme.test
+++ b/modules/simpletest/tests/theme.test
@@ -155,6 +155,16 @@ class ThemeTestCase extends DrupalWebTestCase {
     $this->assertNotEqual(theme_get_setting('subtheme_override', 'test_basetheme'), theme_get_setting('subtheme_override', 'test_subtheme'), 'Base theme\'s default settings values can be overridden by subtheme.');
     $this->assertIdentical(theme_get_setting('basetheme_only', 'test_subtheme'), 'base theme value', 'Base theme\'s default settings values are inherited by subtheme.');
   }
+
+  /**
+   * Test the drupal_add_region_content() function.
+   */
+function testDrupalAddRegionContent() {
+  $this->drupalGet('theme-test/drupal-add-region-content');
+  $this->assertText('Hello');
+  $this->assertText('World');
+}
+
 }
 
 /**
diff --git a/modules/simpletest/tests/theme_test.module b/modules/simpletest/tests/theme_test.module
index 61a12bb..948d817 100644
--- a/modules/simpletest/tests/theme_test.module
+++ b/modules/simpletest/tests/theme_test.module
@@ -53,6 +53,11 @@ function theme_test_menu() {
     'access callback' => TRUE,
     'type' => MENU_CALLBACK,
   );
+  $items['theme-test/drupal-add-region-content'] = array(
+    'page callback' => '_theme_test_drupal_add_region_content',
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK,
+  );
   return $items;
 }
 
@@ -127,6 +132,14 @@ function _theme_test_suggestion() {
 }
 
 /**
+ * Page callback, calls drupal_add_region_content.
+ */
+function _theme_test_drupal_add_region_content() {
+  drupal_add_region_content('content', 'World');
+  return 'Hello';
+}
+
+/**
  * Theme function for testing theme('theme_test_foo').
  */
 function theme_theme_test_foo($variables) {