diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
index e3a11b7..892aafb 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
@@ -417,6 +417,7 @@ public function onDependencyRemoval(array $dependencies) {
   public function serialize() {
     return serialize(array(
       'entity_type_id' => $this->getEntityTypeId(),
+      'is_new' => $this->isNew(),
       'values' => $this->toArray(),
     ));
   }
@@ -430,7 +431,9 @@ public function unserialize($serialized) {
     // that have been serialized through our serialize() method.
     $unserialized = unserialize($serialized);
     if (isset($unserialized['entity_type_id'])) {
-      return $this->__construct($unserialized['values'], $unserialized['entity_type_id']);
+      $entity = $this->__construct($unserialized['values'], $unserialized['entity_type_id']);
+      $entity->enforceIsNew($unserialized['is_new']);
+      return $entity;
     }
   }