diff --git a/core/modules/contact/contact.module b/core/modules/contact/contact.module
index 3ef1ce6..d1c1526 100644
--- a/core/modules/contact/contact.module
+++ b/core/modules/contact/contact.module
@@ -272,8 +272,8 @@ function contact_mail($key, &$message, $params) {
 
   $variables = array(
     '!site-name' => config('system.site')->get('name'),
-    '!subject' => $contact_message->subject,
-    '!category' => isset($params['contact_category']) ? $params['contact_category']->label() : NULL,
+    '!subject' => $contact_message->subject->value,
+    '!category' => !empty($params['contact_category']) ? $params['contact_category']->label() : NULL,
     '!form-url' => url(current_path(), array('absolute' => TRUE, 'language' => $language)),
     '!sender-name' => user_format_name($sender),
   );
@@ -312,7 +312,7 @@ function contact_mail($key, &$message, $params) {
       $message['body'][] = t("!sender-name (!sender-url) has sent you a message via your contact form at !site-name.", $variables, $options);
       $message['body'][] = t("If you don't want to receive such e-mails, you can change your settings at !recipient-edit-url.", $variables, $options);
       $message['body'][] = t('Message:', array(), $options);
-      $message['body'][] = $contact_message->message;
+      $message['body'][] = $contact_message->message->value;
       break;
   }
 }
diff --git a/core/modules/contact/contact.pages.inc b/core/modules/contact/contact.pages.inc
index 423cd72..52834fd 100644
--- a/core/modules/contact/contact.pages.inc
+++ b/core/modules/contact/contact.pages.inc
@@ -45,6 +45,9 @@ function contact_site_page(Category $category = NULL) {
       }
     }
   }
+  else if ($category->id() == 'personal') {
+    throw new NotFoundHttpException();
+  }
   $message = entity_create('contact_message', array(
     'category' => $category->id(),
   ));
diff --git a/core/modules/contact/lib/Drupal/contact/MessageFormController.php b/core/modules/contact/lib/Drupal/contact/MessageFormController.php
index 6f73d96..2a09412 100644
--- a/core/modules/contact/lib/Drupal/contact/MessageFormController.php
+++ b/core/modules/contact/lib/Drupal/contact/MessageFormController.php
@@ -7,13 +7,13 @@
 
 namespace Drupal\contact;
 
-use Drupal\Core\Entity\EntityFormController;
+use Drupal\Core\Entity\EntityFormControllerNG;
 use Drupal\user\Plugin\Core\Entity\User;
 
 /**
  * Form controller for contact message forms.
  */
-class MessageFormController extends EntityFormController {
+class MessageFormController extends EntityFormControllerNG {
 
   /**
    * Overrides Drupal\Core\Entity\EntityFormController::form().
@@ -61,23 +61,22 @@ public function form(array $form, array &$form_state) {
       $form['mail']['#markup'] = check_plain($user->mail);
     }
 
-    // The user contact form only has a recipient, not a category.
-    // @todo Convert user contact form into a locked contact category.
-    if ($message->recipient instanceof User) {
+    // Display the recipient for a personal message.
+    if ($message->category->target_id == 'personal') {
       $form['recipient'] = array(
         '#type' => 'item',
         '#title' => t('To'),
-        '#value' => $message->recipient,
+        '#value' => $message->recipient->entity,
         'name' => array(
           '#theme' => 'username',
-          '#account' => $message->recipient,
+          '#account' => $message->recipient->entity,
         ),
       );
     }
     else {
       $form['category'] = array(
         '#type' => 'value',
-        '#value' => $message->category,
+        '#value' => $message->category->target_id,
       );
     }
 
@@ -146,31 +145,31 @@ public function save(array $form, array &$form_state) {
     if (!$user->uid) {
       // At this point, $sender contains drupal_anonymous_user(), so we need to
       // take over the submitted form values.
-      $sender->name = $message->name;
-      $sender->mail = $message->mail;
+      $sender->name = $message->name->value;
+      $sender->mail = $message->mail->value;
       // Save the anonymous user information to a cookie for reuse.
-      user_cookie_save(array('name' => $message->name, 'mail' => $message->mail));
+      user_cookie_save(array('name' => $message->name->value, 'mail' => $message->mail->value));
       // For the e-mail message, clarify that the sender name is not verified; it
       // could potentially clash with a username on this site.
-      $sender->name = t('!name (not verified)', array('!name' => $message->name));
+      $sender->name = t('!name (not verified)', array('!name' => $message->name->value));
     }
 
     // Build e-mail parameters.
     $params['contact_message'] = $message;
     $params['sender'] = $sender;
 
-    if ($message->category) {
+    if ($message->category->target_id != 'personal') {
       // Send to the category recipient(s), using the site's default language.
-      $category = entity_load('contact_category', $message->category);
+      $category = $message->category->entity;
       $params['contact_category'] = $category;
 
       $to = implode(', ', $category->recipients);
       $recipient_langcode = language_default()->langcode;
     }
-    elseif ($message->recipient instanceof User) {
+    elseif ($message->recipient->target_id) {
       // Send to the user in the user's preferred language.
-      $to = $message->recipient->mail;
-      $recipient_langcode = user_preferred_langcode($message->recipient);
+      $to = $message->recipient->entity->mail;
+      $recipient_langcode = user_preferred_langcode($message->recipient->entity);
     }
     else {
       throw new \RuntimeException(t('Unable to determine message recipient.'));
@@ -180,19 +179,19 @@ public function save(array $form, array &$form_state) {
     drupal_mail('contact', 'page_mail', $to, $recipient_langcode, $params, $sender->mail);
 
     // If requested, send a copy to the user, using the current language.
-    if ($message->copy) {
+    if ($message->copy->value) {
       drupal_mail('contact', 'page_copy', $sender->mail, $language_interface->langcode, $params, $sender->mail);
     }
 
     // If configured, send an auto-reply, using the current language.
-    if ($message->category && $category->reply) {
+    if ($message->category->target_id && $category->reply) {
       // User contact forms do not support an auto-reply message, so this
       // message always originates from the site.
       drupal_mail('contact', 'page_autoreply', $sender->mail, $language_interface->langcode, $params);
     }
 
     \Drupal::service('flood')->register('contact', config('contact.settings')->get('flood.interval'));
-    if ($message->category) {
+    if ($message->category->target_id) {
       watchdog('contact', '%sender-name (@sender-from) sent an e-mail regarding %category.', array(
         '%sender-name' => $sender->name,
         '@sender-from' => $sender->mail,
@@ -211,8 +210,8 @@ public function save(array $form, array &$form_state) {
 
     // To avoid false error messages caused by flood control, redirect away from
     // the contact form; either to the contacted user account or the front page.
-    if ($message->recipient instanceof User && user_access('access user profiles')) {
-      $uri = $message->recipient->uri();
+    if ($message->recipient->target_id && user_access('access user profiles')) {
+      $uri = $message->recipient->entity->uri();
       $form_state['redirect'] = array($uri['path'], $uri['options']);
     }
     else {
diff --git a/core/modules/contact/lib/Drupal/contact/MessageRenderController.php b/core/modules/contact/lib/Drupal/contact/MessageRenderController.php
index b3a8a31..1effe40 100644
--- a/core/modules/contact/lib/Drupal/contact/MessageRenderController.php
+++ b/core/modules/contact/lib/Drupal/contact/MessageRenderController.php
@@ -24,11 +24,11 @@ public function buildContent(array $entities, array $displays, $view_mode, $lang
     foreach ($entities as $entity) {
       // Add the message extra field, if enabled.
       $display = $displays[$entity->bundle()];
-      if (!empty($entity->message) && $display->getComponent('message')) {
+      if ($entity->message->value && $display->getComponent('message')) {
         $entity->content['message'] = array(
           '#type' => 'item',
           '#title' => t('Message'),
-          '#markup' => check_plain($entity->message),
+          '#markup' => check_plain($entity->message->value),
         );
       }
     }
diff --git a/core/modules/contact/lib/Drupal/contact/MessageStorageController.php b/core/modules/contact/lib/Drupal/contact/MessageStorageController.php
new file mode 100644
index 0000000..927fa2d
--- /dev/null
+++ b/core/modules/contact/lib/Drupal/contact/MessageStorageController.php
@@ -0,0 +1,61 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\contact\MessageStorageController.
+ */
+
+namespace Drupal\contact;
+
+use Drupal\Core\Entity\DatabaseStorageControllerNG;
+
+/**
+ * Defines the controller class for the contact message entity.
+ */
+class MessageStorageController extends DatabaseStorageControllerNG {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function baseFieldDefinitions() {
+    $fields['category'] = array(
+      'label' => t('Category'),
+      'description' => t('The ID of the associated category.'),
+      'type' => 'entity_reference_field',
+      'settings' => array('target_type' => 'contact_category'),
+    );
+    $fields['name'] = array(
+      'label' => t("The sender's name"),
+      'description' => t('The name of the person that is sending the contact message.'),
+      'type' => 'string_field',
+    );
+    $fields['mail'] = array(
+      'label' => t("The sender's e-mail"),
+      'description' => t('The e-mail of the person that is sending the contact message.'),
+      'type' => 'string_field',
+    );
+    $fields['subject'] = array(
+      'label' => t("The message subject"),
+      'description' => t('The subject of the contact message.'),
+      'type' => 'string_field',
+    );
+    $fields['message'] = array(
+      'label' => t("The message text"),
+      'description' => t('The text of the contact message.'),
+      'type' => 'string_field',
+    );
+    $fields['copy'] = array(
+      'label' => t("Copy"),
+      'description' => t('Whether to send a copy of the message to the sender.'),
+      'type' => 'string_field',
+    );
+    $fields['recipient'] = array(
+      'label' => t('Recipient ID'),
+      'description' => t('The ID of the recipient user.'),
+      'type' => 'entity_reference_field',
+      'settings' => array('target_type' => 'user'),
+      'translatable' => TRUE,
+    );
+    return $fields;
+  }
+}
diff --git a/core/modules/contact/lib/Drupal/contact/Plugin/Core/Entity/Message.php b/core/modules/contact/lib/Drupal/contact/Plugin/Core/Entity/Message.php
index 3bec9e9..bd5584f 100644
--- a/core/modules/contact/lib/Drupal/contact/Plugin/Core/Entity/Message.php
+++ b/core/modules/contact/lib/Drupal/contact/Plugin/Core/Entity/Message.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Entity\Annotation\EntityType;
 use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Entity\Entity;
+use Drupal\Core\Entity\EntityNG;
 use Drupal\contact\MessageInterface;
 
 /**
@@ -20,7 +21,7 @@
  *   label = @Translation("Contact message"),
  *   module = "contact",
  *   controllers = {
- *     "storage" = "Drupal\Core\Entity\DatabaseStorageController",
+ *     "storage" = "Drupal\contact\MessageStorageController",
  *     "render" = "Drupal\contact\MessageRenderController",
  *     "form" = {
  *       "default" = "Drupal\contact\MessageFormController"
@@ -35,7 +36,7 @@
  *   }
  * )
  */
-class Message extends Entity implements MessageInterface {
+class Message extends EntityNG implements MessageInterface {
 
   /**
    * The contact category ID of this message.
@@ -104,11 +105,15 @@ public function id() {
     return NULL;
   }
 
-  /**
-   * Overrides Drupal\Core\Entity\Entity::bundle().
-   */
-  public function bundle() {
-    return $this->category;
+  protected function init() {
+    parent::init();
+    unset($this->name);
+    unset($this->message);
+    unset($this->mail);
+    unset($this->category);
+    unset($this->copy);
+    unset($this->recipient);
+    unset($this->subject);
   }
 
   /**