diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
index cf74af5..905ac98 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityUnitTest.php
@@ -50,16 +50,18 @@ public function testCreatingConflictingEntities() {
     $entity->save();
 
     // Create an entity with the same ID, but a different label.
+    $exception = FALSE;
     try {
       $entity = entity_create('config_test', array('id' => 'foo', 'label' => 'Bananas'));
       $entity->save();
     }
     catch (EntityMalformedException $e) {
-      $this->pass('A conflicting entity was not saved.');
+      $exception = TRUE;
     }
     // 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.');
+    $this->assertTrue($exception, 'An exception was thrown when creating an entity with a duplicate ID.');
   }
 
 }