diff --git a/content_entity_example/src/ContactInterface.php b/content_entity_example/src/ContactInterface.php
index c9501cb..f87ded2 100755
--- a/content_entity_example/src/ContactInterface.php
+++ b/content_entity_example/src/ContactInterface.php
@@ -8,11 +8,11 @@ namespace Drupal\content_entity_example;
 
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\user\EntityOwnerInterface;
-
+use Drupal\Core\Entity\EntityChangedInterface;
 /**
  * Provides an interface defining a Contact entity.
  * @ingroup content_entity_example
  */
-interface ContactInterface extends ContentEntityInterface, EntityOwnerInterface {
+interface ContactInterface extends ContentEntityInterface, EntityOwnerInterface, EntityChangedInterface {
 
 }
diff --git a/content_entity_example/src/Entity/Contact.php b/content_entity_example/src/Entity/Contact.php
index b8e40d2..4a50861 100755
--- a/content_entity_example/src/Entity/Contact.php
+++ b/content_entity_example/src/Entity/Contact.php
@@ -12,6 +12,7 @@ use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\content_entity_example\ContactInterface;
 use Drupal\user\UserInterface;
+use Drupal\Core\Entity\EntityChangedTrait;
 
 /**
  * Defines the ContentEntityExample entity.
@@ -127,6 +128,7 @@ use Drupal\user\UserInterface;
  * field.
  */
 class Contact extends ContentEntityBase implements ContactInterface {
+  use EntityChangedTrait;
 
   /**
    * {@inheritdoc}