diff --git a/src/Form/DummyimageAdminForm.php b/src/Form/DummyimageAdminForm.php
index 7636350..47471cc 100644
--- a/src/Form/DummyimageAdminForm.php
+++ b/src/Form/DummyimageAdminForm.php
@@ -23,6 +23,15 @@ class DummyimageAdminForm extends ConfigFormBase {
   /**
    * {@inheritdoc}
    */
+  protected function getEditableConfigNames() {
+    return [
+      'dummyimage.settings',
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $config = $this->config('dummyimage.settings');
 
@@ -52,14 +61,14 @@ class DummyimageAdminForm extends ConfigFormBase {
     }
 
     $options = array(
-      'none' => t('For no images'),
-      'missing' => t('For missing images'),
-      'all' => t('For all images'),
+      'none' => $this->t('For no images'),
+      'missing' => $this->t('For missing images'),
+      'all' => $this->t('For all images'),
     );
 
     $form['dummyimages_generate'] = array(
       '#type' => 'radios',
-      '#title' => t('Use dummy images'),
+      '#title' => $this->t('Use dummy images'),
       '#options' => $options,
       '#default_value' => \Drupal::config('dummyimage.settings')
         ->get('dummyimages_generate'),
@@ -69,13 +78,14 @@ class DummyimageAdminForm extends ConfigFormBase {
     $plugins = $manager->getDefinitions();
     $service_names = array();
     foreach ($plugins as $plugin) {
-      $service_names[$plugin['id']] = $this->t($plugin['name']);
+      $plugin_name = (string) $plugin['name'];
+      $service_names[$plugin['id']] = $this->t($plugin_name);
     }
 
     $form['dummyimages_service'] = array(
       '#type' => 'select',
-      '#title' => t('Service'),
-      '#description' => t('Select a image service to use'),
+      '#title' => $this->t('Service'),
+      '#description' => $this->t('Select a image service to use'),
       '#default_value' => \Drupal::config('dummyimage.settings')
         ->get('dummyimages_service'),
       '#options' => $service_names,