diff --git a/core/modules/contact/contact.admin.inc b/core/modules/contact/contact.admin.inc
index bc706c3..6bc8ed3 100644
--- a/core/modules/contact/contact.admin.inc
+++ b/core/modules/contact/contact.admin.inc
@@ -17,7 +17,7 @@
  */
 function contact_category_list() {
   drupal_set_title(t('Contact form categories'));
-  return drupal_container()->get('plugin.manager.entity')
+  return Drupal::service('plugin.manager.entity')
     ->getListController('contact_category')
     ->render();
 }
diff --git a/core/modules/contact/lib/Drupal/contact/CategoryListController.php b/core/modules/contact/lib/Drupal/contact/CategoryListController.php
index b7d9091..058979a 100644
--- a/core/modules/contact/lib/Drupal/contact/CategoryListController.php
+++ b/core/modules/contact/lib/Drupal/contact/CategoryListController.php
@@ -8,11 +8,19 @@
 
 use Drupal\Core\Config\Entity\ConfigEntityListController;
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Form\FormInterface;
 
 /**
  * Provides a listing of contact categories.
  */
-class CategoryListController extends ConfigEntityListController {
+class CategoryListController extends ConfigEntityListController implements FormInterface {
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::getFormID().
+   */
+  public function getFormID() {
+    return 'contact_category_list_form';
+  }
 
   /**
    * Overrides \Drupal\Core\Entity\EntityListController::getOperations().
@@ -66,28 +74,17 @@ public function buildRow(EntityInterface $entity) {
   public function render() {
     $entities = $this->load();
     if (count($entities) > 1) {
-      $form_state = array();
-      $form_state['build_info']['args'] = array();
-      $form_state['build_info']['callback'] = array($this, 'form');
-
-      return drupal_build_form($this->entityType . '_list_form', $form_state);
+      // Creates a form for manipulating contact category form weights.
+      return drupal_get_form($this);
     }
 
     return parent::render();
   }
 
   /**
-   * Creates a tabledrag form for manipulating contact category form weights.
-   *
-   * @param array $form
-   *   An associative array containing the structure of the form.
-   * @param array $form_state
-   *   A reference to a keyed array containing the current state of the form.
-   *
-   * @return array
-   *   The array containing the complete form.
+   * Implements \Drupal\Core\Form\FormInterface::buildForm().
    */
-  function form($form, $form_state) {
+  public function buildForm(array $form, array &$form_state) {
     $form['entities'] = array(
       '#type' => 'table',
       '#header' => $this->buildHeader() + array('weight' => t('Weight')),
@@ -138,7 +135,6 @@ function form($form, $form_state) {
     $form['actions']['submit'] = array(
       '#type' => 'submit',
       '#value' => t('Save changes'),
-      '#submit' => array(array($this, 'submit')),
       '#button_type' => 'primary',
     );
 
@@ -146,14 +142,16 @@ function form($form, $form_state) {
   }
 
   /**
-   * Submit handler for the overview form.
-   *
-   * @param array $form
-   *   An associative array containing the structure of the form.
-   * @param array $form_state
-   *   A reference to a keyed array containing the current state of the form.
+   * Implements \Drupal\Core\Form\FormInterface::validateForm().
+   */
+  public function validateForm(array &$form, array &$form_state) {
+    // No validation.
+  }
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::submitForm().
    */
-  public function submit($form, &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $values = $form_state['values']['entities'];
 
     $entities = entity_load_multiple($this->entityType, array_keys($values));