diff -u b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
--- b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
+++ b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
@@ -73,10 +73,8 @@
       throw new UnexpectedValueException('The type link relation must be specified.');
     }
 
-    // Get language. language_default() is used because otherwise the entity
-    // system cannot understand the langcode when working in the DrupalUnitTest
-    // environment and importing data without an explicit langcode.
-    $langcode = isset($data['langcode']) ? $data['langcode'][0]['value'] : language_default();
+    // Get language.
+    $langcode = isset($data['langcode']) ? $data['langcode'][0]['value'] : LANGUAGE_NOT_SPECIFIED;
 
     // Create the entity.
     $typed_data_ids = $this->getTypedDataIds($data['_links']['type']);
diff -u b/core/modules/hal/lib/Drupal/hal/Tests/DenormalizeTest.php b/core/modules/hal/lib/Drupal/hal/Tests/DenormalizeTest.php
--- b/core/modules/hal/lib/Drupal/hal/Tests/DenormalizeTest.php
+++ b/core/modules/hal/lib/Drupal/hal/Tests/DenormalizeTest.php
@@ -136,12 +136,10 @@
         array(
           'value' => $this->randomName(),
           'format' => 'full_html',
-          'lang' => 'en',
         ),
         array(
           'value' => $this->randomName(),
           'format' => 'filtered_html',
-          'lang' => 'en',
         ),
         array(
           'value' => $this->randomName(),
@@ -156,7 +154,7 @@
       ),
     );
 
-    $expected_value_en = array(
+    $expected_value_default = array(
       array (
         'value' => $data['field_test_translatable_text'][0]['value'],
         'format' => 'full_html',
@@ -179,7 +177,7 @@
     $denormalized = $this->serializer->denormalize($data, $this->entityClass, $this->format);
     $this->assertEqual($data['uuid'], $denormalized->get('uuid')->getValue(), 'A preset value (e.g. UUID) is overridden by incoming data.');
     $this->assertEqual($data['field_test_text'], $denormalized->get('field_test_text')->getValue(), 'A basic text field is denormalized.');
-    $this->assertEqual($expected_value_en, $denormalized->get('field_test_translatable_text')->getValue(), 'Values in the default language are properly handled for a translatable field.');
+    $this->assertEqual($expected_value_default, $denormalized->get('field_test_translatable_text')->getValue(), 'Values in the default language are properly handled for a translatable field.');
     $this->assertEqual($expected_value_de, $denormalized->getTranslation('de')->get('field_test_translatable_text')->getValue(), 'Values in a translation language are properly handled for a translatable field.');
   }
 }