diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php
new file mode 100644
index 0000000..9b3dc3a
--- /dev/null
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Type/TaxonomyTermReferenceItem.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\taxonomy\Type\taxonomyItem.
+ */
+
+namespace Drupal\taxonomy\Type;
+
+use Drupal\Core\Entity\Field\Type\EntityReferenceItem;
+
+/**
+ * Defines the 'taxonomy_term_reference' entity field item.
+ */
+class TaxonomyTermReferenceItem extends EntityReferenceItem {
+
+  /**
+   * Implements ComplexDataInterface::getPropertyDefinitions().
+   */
+  public function getPropertyDefinitions() {
+
+    if (!isset(self::$propertyDefinitions)) {
+      self::$propertyDefinitions['tid'] = array(
+        'type' => 'integer',
+        'label' => t('Referenced taxonomy term id.'),
+      );
+      self::$propertyDefinitions['entity'] = array(
+        'type' => 'entity',
+        'constraints' => array(
+          'entity type' => 'taxonomy_term',
+        ),
+        'label' => t('Entity'),
+        'description' => t('The referenced entity'),
+        // The entity object is computed out of the tid.
+        'computed' => TRUE,
+        'read-only' => FALSE,
+        'settings' => array('id source' => 'tid'),
+      );
+    }
+    return self::$propertyDefinitions;
+  }
+
+}
diff --git a/core/modules/taxonomy/taxonomy.module b/core/modules/taxonomy/taxonomy.module
index 8da637f..bb2961a 100644
--- a/core/modules/taxonomy/taxonomy.module
+++ b/core/modules/taxonomy/taxonomy.module
@@ -1015,6 +1015,7 @@ function taxonomy_field_info() {
       'description' => t('This field stores a reference to a taxonomy term.'),
       'default_widget' => 'options_select',
       'default_formatter' => 'taxonomy_term_reference_link',
+      'field item class' => 'Drupal\taxonomy\Type\TaxonomyTermReferenceItem',
       'settings' => array(
         'allowed_values' => array(
           array(