diff --git a/src/Form/SettingsForm.php b/src/Form/SettingsForm.php
index 55c6f64..bc28aca 100644
--- a/src/Form/SettingsForm.php
+++ b/src/Form/SettingsForm.php
@@ -4,12 +4,34 @@ namespace Drupal\notify_to_slack\Form;
 
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
 
 /**
  * Configuration form to collect the url, channel name and other details.
  */
 class SettingsForm extends ConfigFormBase {
 
+  protected $entityTypeManager;
+
+  protected $config_factory;
+
+  public function __construct(ConfigFactoryInterface $config_factory, EntityTypeManagerInterface $entityTypeManager) {
+    parent::__construct($config_factory);
+    $this->entityTypeManager = $entityTypeManager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+    public static function create(ContainerInterface $container) {
+      return new static(
+        $container->get('config.factory'),
+        $container->get('entity_type.manager')
+      );
+    }
+
   /**
    * {@inheritdoc}
    */
@@ -49,7 +71,8 @@ class SettingsForm extends ConfigFormBase {
       '#default_value' => $config->get('webhook_name'),
       '#description' => $this->t('Enter display name of the notifier'),
     ];
-    $contentTypes = \Drupal::service('entity.manager')->getStorage('node_type')->loadMultiple();
+    $contentTypes = $this->entityTypeManager->getStorage('node_type')->loadMultiple();
+
     $contentTypesList = [];
     foreach ($contentTypes as $contentType) {
       $contentTypesList[$contentType->id()] = $contentType->label();