diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
index 37aa854..bc3655c 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigCRUDTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\config\Tests;
 
 use Drupal\Core\Config\DatabaseStorage;
+use Drupal\Core\Config\ConfigException;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -112,4 +113,28 @@ class ConfigCRUDTest extends WebTestBase {
     // their order must be identical.
     $this->assertIdentical($new_config->get(), $config->get());
   }
+  /**
+   * Tests saving a config object without a namespace.
+   */
+  function testNamespace() {
+    $name = 'nonamespace';
+    try {
+      $config = config($name);
+      $config->save();
+      $this->fail('Expected exception ConfigException was not thrown.');
+    }
+    catch (ConfigException $e) {
+      $this->pass('Expected exception ConfigException was thrown.');
+    }
+
+    $name = 'config.namespace';
+    try {
+      $config = config($name);
+      $config->save();
+      $this->pass('Exception ConfigException was not thrown.');
+    }
+    catch (ConfigException $e) {
+      $this->fail('Exception ConfigException was thrown.');
+    }
+  }
 }