diff --git a/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
index c47a72c..751de28 100644
--- a/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
+++ b/core/modules/hal/lib/Drupal/hal/Normalizer/EntityNormalizer.php
@@ -66,6 +66,18 @@ public function normalize($entity, $format = NULL, array $context = array()) {
   /**
    * Implements \Symfony\Component\Serializer\Normalizer\DenormalizerInterface::denormalize().
    *
+   * @param array $data
+   *   Entity data to restore.
+   * @param string $class
+   *   Unused, entity_create() is used to instantiate entity objects.
+   * @param string $format
+   *   Format the given data was extracted from.
+   * @param array $context
+   *   Options available to the denormalizer. Keys that can be used:
+   *   - request_method: if set to "patch" the denormalization will clear out
+   *     all default values for entity fields before applying $data to the
+   *     entity.
+   *
    * @throws \Symfony\Component\Serializer\Exception\UnexpectedValueException
    */
   public function denormalize($data, $class, $format = NULL, array $context = array()) {
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php b/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
index eca41bc..641d541 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/UpdateTest.php
@@ -65,8 +65,18 @@ public function testPatchUpdate() {
     $entity = entity_load($entity_type, $entity->id(), TRUE);
     $this->assertEqual($entity->field_test_text->value, $patch_entity->field_test_text->value, 'Field was successfully updated.');
 
-    // Try to empty a field.
+    // Make sure that the field does not get deleted if it is not present in the
+    // PATCH request.
     $normalized = $serializer->normalize($patch_entity, $this->defaultFormat);
+    unset($normalized['field_test_text']);
+    $serialized = $serializer->encode($normalized, $this->defaultFormat);
+    $this->httpRequest('entity/' . $entity_type . '/' . $entity->id(), 'PATCH', $serialized, $this->defaultMimeType);
+    $this->assertResponse(204);
+
+    $entity = entity_load($entity_type, $entity->id(), TRUE);
+    $this->assertNotNull($entity->field_test_text->value. 'Test field has not been deleted.');
+
+    // Try to empty a field.
     $normalized['field_test_text'] = array();
     $serialized = $serializer->encode($normalized, $this->defaultFormat);