diff --git a/src/Form/RequiredContext.php b/src/Form/RequiredContext.php
index cfeeb28..3d724db 100644
--- a/src/Form/RequiredContext.php
+++ b/src/Form/RequiredContext.php
@@ -9,6 +9,7 @@ use Drupal\Core\Form\FormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\Form\FormBuilder;
 
 abstract class RequiredContext extends FormBase {
 
@@ -17,6 +18,13 @@ abstract class RequiredContext extends FormBase {
    */
   protected $typedDataManager;
 
+  /**
+   * The buider of form.
+   *
+   * @var \Drupal\Core\Form\FormBuilder
+   */
+  protected $formBuilder;
+
   /**
    * @var string
    */
@@ -26,11 +34,15 @@ abstract class RequiredContext extends FormBase {
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container) {
-    return new static($container->get('typed_data_manager'));
+    return new static(
+      $container->get('typed_data_manager'),
+      $container->get('form_builder')
+    );
   }
 
-  public function __construct(PluginManagerInterface $typed_data_manager) {
+  public function __construct(PluginManagerInterface $typed_data_manager, FormBuilder $form_builder) {
     $this->typedDataManager = $typed_data_manager;
+    $this->formBuilder = $form_builder;
   }
 
   /**
@@ -98,7 +110,7 @@ abstract class RequiredContext extends FormBase {
    */
   public function add(array &$form, FormStateInterface $form_state) {
     $context = $form_state->getValue('contexts');
-    $content = \Drupal::formBuilder()->getForm($this->getContextClass(), $context, $this->getTempstoreId(), $this->machine_name);
+    $content = $this->formBuilder->getForm($this->getContextClass(), $context, $this->getTempstoreId(), $this->machine_name);
     $content['#attached']['library'][] = 'core/drupal.dialog.ajax';
     $response = new AjaxResponse();
     $response->addCommand(new OpenModalDialogCommand($this->t('Configure Required Context'), $content, array('width' => '700')));