diff --git a/core/modules/path/src/Plugin/Field/FieldType/PathFieldItemList.php b/core/modules/path/src/Plugin/Field/FieldType/PathFieldItemList.php
index 8488c7e..1a5fbe0 100644
--- a/core/modules/path/src/Plugin/Field/FieldType/PathFieldItemList.php
+++ b/core/modules/path/src/Plugin/Field/FieldType/PathFieldItemList.php
@@ -18,6 +18,12 @@ class PathFieldItemList extends FieldItemList {
    * {@inheritdoc}
    */
   protected function computeValue() {
+    // Default the langcode to the current language if this is a new entity or
+    // there is no alias for an existent entity.
+    // @todo Set the langcode to not specified for untranslatable fields
+    //   in https://www.drupal.org/node/2689459.
+    $value = ['langcode' => $this->getLangcode()];
+
     $entity = $this->getEntity();
     if (!$entity->isNew()) {
       // @todo Support loading languge neutral aliases in
@@ -30,16 +36,9 @@ protected function computeValue() {
       if ($alias) {
         $value = $alias;
       }
-      else {
-        // If there is no existing alias, default the langcode to the current
-        // language.
-        // @todo Set the langcode to not specified for untranslatable fields
-        //   in https://www.drupal.org/node/2689459.
-        $value = ['langcode' => $this->getLangcode()];
-      }
-
-      $this->list[0] = $this->createItem(0, $value);
     }
+
+    $this->list[0] = $this->createItem(0, $value);
   }
 
   /**
diff --git a/core/modules/path/src/Plugin/Field/FieldType/PathItem.php b/core/modules/path/src/Plugin/Field/FieldType/PathItem.php
index ea21dac..65cb14b 100644
--- a/core/modules/path/src/Plugin/Field/FieldType/PathItem.php
+++ b/core/modules/path/src/Plugin/Field/FieldType/PathItem.php
@@ -47,14 +47,16 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
    * {@inheritdoc}
    */
   public function isEmpty() {
-    return ($this->alias === NULL || $this->alias === '') && ($this->pid === NULL || $this->pid === '');
+    return ($this->alias === NULL || $this->alias === '') && ($this->pid === NULL || $this->pid === '') && ($this->langcode === NULL || $this->langcode === '');
   }
 
   /**
    * {@inheritdoc}
    */
   public function preSave() {
-    $this->alias = trim($this->alias);
+    if ($this->alias !== NULL) {
+      $this->alias = trim($this->alias);
+    }
   }
 
   /**
diff --git a/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php b/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php
index ad3f02e..d3abef6 100644
--- a/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php
+++ b/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php
@@ -22,7 +22,6 @@ public function normalize($entity, $format = NULL, array $context = []) {
 
     $attributes = [];
     foreach ($entity as $name => $field_items) {
-      $field_items->filterEmptyItems();
       if ($field_items->access('view', $context['account'])) {
         $attributes[$name] = $this->serializer->normalize($field_items, $format, $context);
       }