diff --git a/core/modules/hal/src/Normalizer/ContentEntityNormalizer.php b/core/modules/hal/src/Normalizer/ContentEntityNormalizer.php
index a6ba04049a..6a54b3c502 100644
--- a/core/modules/hal/src/Normalizer/ContentEntityNormalizer.php
+++ b/core/modules/hal/src/Normalizer/ContentEntityNormalizer.php
@@ -171,6 +171,10 @@ public function denormalize($data, $class, $format = NULL, array $context = arra
 
     $this->denormalizeFieldData($data, $entity, $format, $context);
 
+    // Pass the names of the fields whose values can be merged.
+    // @todo https://www.drupal.org/node/2456257 remove this.
+    $entity->_restSubmittedFields = array_keys($data);
+
     return $entity;
   }
 
diff --git a/core/modules/serialization/src/Normalizer/EntityNormalizer.php b/core/modules/serialization/src/Normalizer/EntityNormalizer.php
index c332c4d79f..84baec94be 100644
--- a/core/modules/serialization/src/Normalizer/EntityNormalizer.php
+++ b/core/modules/serialization/src/Normalizer/EntityNormalizer.php
@@ -55,6 +55,10 @@ public function denormalize($data, $class, $format = NULL, array $context = [])
       $entity = $this->entityManager->getStorage($entity_type_id)->create($data);
     }
 
+    // Pass the names of the fields whose values can be merged.
+    // @todo https://www.drupal.org/node/2456257 remove this.
+    $entity->_restSubmittedFields = array_keys($data);
+
     return $entity;
   }
 
diff --git a/core/modules/serialization/src/Normalizer/FieldableEntityNormalizerTrait.php b/core/modules/serialization/src/Normalizer/FieldableEntityNormalizerTrait.php
index aebf48ac7a..516885374f 100644
--- a/core/modules/serialization/src/Normalizer/FieldableEntityNormalizerTrait.php
+++ b/core/modules/serialization/src/Normalizer/FieldableEntityNormalizerTrait.php
@@ -119,10 +119,6 @@ protected function extractBundleData(array &$data, EntityTypeInterface $entity_t
    *   The context data.
    */
   protected function denormalizeFieldData(array $data, FieldableEntityInterface $entity, $format, array $context) {
-    // Pass the names of the fields whose values can be merged.
-    // @todo https://www.drupal.org/node/2456257 remove this.
-    $entity->_restSubmittedFields = array_keys($data);
-
     foreach ($data as $field_name => $field_data) {
       $field_item_list = $entity->get($field_name);