diff --git a/core/modules/translation_entity/lib/Drupal/translation_entity/FieldTranslationSynchronizer.php b/core/modules/translation_entity/lib/Drupal/translation_entity/FieldTranslationSynchronizer.php
index 929d491..c6ebff5 100644
--- a/core/modules/translation_entity/lib/Drupal/translation_entity/FieldTranslationSynchronizer.php
+++ b/core/modules/translation_entity/lib/Drupal/translation_entity/FieldTranslationSynchronizer.php
@@ -95,7 +95,9 @@ public function synchronizeFields(EntityInterface $entity, $sync_langcode, $orig
    * {@inheritdoc}
    */
   public function synchronizeItems(EntityInterface $entity, $field_name, FieldInterface $unchanged_items, $sync_langcode, array $translations, array $columns) {
-    $source_items = $entity->getTranslation($sync_langcode)->{$field_name};
+    // Clone the object, since we are going to access the values after writing
+    // to the entity.
+    $source_items = clone $entity->getTranslation($sync_langcode)->{$field_name};
 
     // Make sure we can detect any change in the source items.
     $change_map = array();
@@ -194,7 +196,7 @@ public function synchronizeItems(EntityInterface $entity, $field_name, FieldInte
   /**
    * Computes a hash code for the specified item.
    *
-   * @param array $items
+   * @param \Drupal\Core\Entity\Field\FieldInterface $items
    *   An array of field items.
    * @param integer $delta
    *   The delta identifying the item to be processed.