diff --git a/core/modules/system/tests/theme.test b/core/modules/system/tests/theme.test
index d7c6fb2..e88afab 100644
--- a/core/modules/system/tests/theme.test
+++ b/core/modules/system/tests/theme.test
@@ -7,6 +7,7 @@
 
 use Drupal\simpletest\WebTestBase;
 use Drupal\simpletest\UnitTestBase;
+use Drupal\test_theme\ThemeClass;
 
 /**
  * Unit tests for the Theme API.
@@ -170,6 +171,13 @@ class ThemeUnitTest extends WebTestBase {
     module_enable(array('theme_test'), FALSE);
     $this->assertIdentical(theme('theme_test_foo', array('foo' => 'c')), 'c', 'The theme registry contains theme_test_foo again after re-enabling the module.');
   }
+
+  /**
+   * Tests theme can provide classes.
+   */
+  function testClassLoading() {
+    new ThemeClass();
+  }
 }
 
 /**
diff --git a/core/modules/system/tests/themes/test_theme/lib/Drupal/test_theme/ThemeClass.php b/core/modules/system/tests/themes/test_theme/lib/Drupal/test_theme/ThemeClass.php
new file mode 100644
index 0000000..eec20a3
--- /dev/null
+++ b/core/modules/system/tests/themes/test_theme/lib/Drupal/test_theme/ThemeClass.php
@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\test_theme\ThemeClass.
+ */
+
+namespace Drupal\test_theme;
+
+/**
+ * Represents a random class, used to test if themes can provide classes.
+ */
+class ThemeClass { }