diff --git a/core/modules/serialization/lib/Drupal/serialization/Tests/EntitySerializationTest.php b/core/modules/serialization/lib/Drupal/serialization/Tests/EntitySerializationTest.php
index bde69ed..0457478 100644
--- a/core/modules/serialization/lib/Drupal/serialization/Tests/EntitySerializationTest.php
+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/EntitySerializationTest.php
@@ -121,7 +121,7 @@ public function testNormalize() {
     $normalized = $this->serializer->normalize($this->entity);
 
     foreach (array_keys($expected) as $fieldName) {
-      $this->assertEqual($expected[$fieldName], $normalized[$fieldName]);
+      $this->assertEqual($expected[$fieldName], $normalized[$fieldName], "ComplexDataNormalizer produces expected array for $fieldName.");
     }
     $this->assertEqual(array_diff_key($normalized, $expected), array(), 'No unexpected data is added to the normalized array.');
   }