diff --git a/core/modules/comment/src/Tests/CommentTypeTest.php b/core/modules/comment/src/Tests/CommentTypeTest.php
index 7005bc1..4e75006 100644
--- a/core/modules/comment/src/Tests/CommentTypeTest.php
+++ b/core/modules/comment/src/Tests/CommentTypeTest.php
@@ -83,7 +83,7 @@ public function testCommentTypeCreation() {
     $this->assertTrue($comment_type, 'The new comment type has been created.');
 
     // Check that the comment type was created in site default language.
-    $default_langcode = \Drupal::languageManager()->getDefaultLanguage()->id;
+    $default_langcode = \Drupal::languageManager()->getDefaultLanguage()->getId();
     $this->assertEqual($comment_type->langcode, $default_langcode);
   }
 
diff --git a/core/modules/system/src/Tests/Entity/EntityFieldDefaultValueTest.php b/core/modules/system/src/Tests/Entity/EntityFieldDefaultValueTest.php
index 61b9aae..1e7af85 100644
--- a/core/modules/system/src/Tests/Entity/EntityFieldDefaultValueTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityFieldDefaultValueTest.php
@@ -67,7 +67,7 @@ public function testDefaultValueCallback() {
     $entity = $this->entityManager->getStorage('entity_test_default_value')->create();
     // The description field has a default value callback for testing, see
     // entity_test_field_default_value().
-    $this->assertEqual($entity->description->value, 'description_' . $entity->language()->id);
+    $this->assertEqual($entity->description->value, 'description_' . $entity->language()->getId());
   }
 
 }
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.module b/core/modules/system/tests/modules/entity_test/entity_test.module
index 912dc7d..a18d92e 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.module
+++ b/core/modules/system/tests/modules/entity_test/entity_test.module
@@ -430,7 +430,7 @@ function entity_test_entity_test_mul_translation_delete(EntityInterface $transla
  * @see \Drupal\field\Entity\FieldInstanceConfig::$default_value
  */
 function entity_test_field_default_value(ContentEntityInterface $entity, FieldDefinitionInterface $definition) {
-  return array(array('value' => $definition->getName() . '_' . $entity->language()->id));
+  return array(array('value' => $definition->getName() . '_' . $entity->language()->getId()));
 }
 
 /**