diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
index d64c73a..cf74af5 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\config\Tests;
 
 use Drupal\simpletest\DrupalUnitTestBase;
+use Drupal\Core\Entity\EntityMalformedException;
 
 /**
  * Unit tests for configuration controllers and objects.
@@ -40,4 +41,25 @@ public function testStorageControllerMethods() {
     $this->assertIdentical($controller->getConfigPrefix(), $expected);
   }
 
+  /**
+   * Tests the behavior of creating conflicting entities.
+   */
+  public function testCreatingConflictingEntities() {
+    // Create an entity with a label.
+    $entity = entity_create('config_test', array('id' => 'foo', 'label' => 'Foo', 'style' => 'foo'));
+    $entity->save();
+
+    // Create an entity with the same ID, but a different label.
+    try {
+      $entity = entity_create('config_test', array('id' => 'foo', 'label' => 'Bananas'));
+      $entity->save();
+    }
+    catch (EntityMalformedException $e) {
+      $this->pass('A conflicting entity was not saved.');
+    }
+    // Creating an entity with the same machine name should not succeed.
+    $this->assertEqual($entity->label(), 'Foo', 'The entity label was not overwritten.');
+    $this->assertEqual($entity->style, 'foo', 'The entity style was not overwritten.');
+  }
+
 }