diff --git a/simplenews.api.php b/simplenews.api.php
index 6c0e59c..b55f748 100644
--- a/simplenews.api.php
+++ b/simplenews.api.php
@@ -69,7 +69,7 @@
 function hook_simplenews_issue_operations() {
   $operations = array(
     'activate' => array(
-      'label' => t('Send'),
+      'label' => $this->t('Send'),
       'callback' => 'simplenews_issue_send',
     ),
   );
@@ -84,17 +84,17 @@ function hook_simplenews_issue_operations() {
 function hook_simplenews_subscription_operations() {
   $operations = array(
     'activate' => array(
-      'label' => t('Activate'),
+      'label' => $this->t('Activate'),
       'callback' => 'simplenews_subscription_activate',
       'callback arguments' => array(\Drupal\simplenews\SubscriberInterface::ACTIVE),
     ),
     'inactivate' => array(
-      'label' => t('Inactivate'),
+      'label' => $this->t('Inactivate'),
       'callback' => 'simplenews_subscription_activate',
       'callback arguments' => array(\Drupal\simplenews\SubscriberInterface::INACTIVE),
     ),
     'delete' => array(
-      'label' => t('Delete'),
+      'label' => $this->t('Delete'),
       'callback' => 'simplenews_subscription_delete_multiple',
     ),
   );
@@ -198,12 +198,12 @@ function hook_simplenews_unsubscribe(SimplenewsSubscriber $subscriber, $subscrip
 function hook_simplenews_source_cache_info() {
   return array(
     'SimplenewsSourceCacheNone' => array(
-      'label' => t('No caching'),
-      'description' => t('This allows to theme each newsletter separately.'),
+      'label' => $this->t('No caching'),
+      'description' => $this->t('This allows to theme each newsletter separately.'),
     ),
     'SimplenewsSourceCacheBuild' => array(
-      'label' => t('Cached content source'),
-      'description' => t('This caches the rendered content to be sent for multiple recipients. It is not possible to use subscriber specific theming but tokens can be used for personalization.'),
+      'label' => $this->t('Cached content source'),
+      'description' => $this->t('This caches the rendered content to be sent for multiple recipients. It is not possible to use subscriber specific theming but tokens can be used for personalization.'),
     ),
   );
 }
diff --git a/src/Controller/ConfirmationController.php b/src/Controller/ConfirmationController.php
index f9d0947..3f2ac2c 100644
--- a/src/Controller/ConfirmationController.php
+++ b/src/Controller/ConfirmationController.php
@@ -46,7 +46,7 @@ class ConfirmationController extends ControllerBase {
 
     // Redirect and display message if no changes are available.
     if ($subscriber && !$subscriber->getChanges()) {
-      drupal_set_message(t('All changes to your subscriptions where already applied. No changes made.'));
+      drupal_set_message($this->t('All changes to your subscriptions where already applied. No changes made.'));
       return $this->redirect('<front>');
     }
 
@@ -87,7 +87,7 @@ class ConfirmationController extends ControllerBase {
         $subscriber->setChanges(array());
         $subscriber->save();
 
-        drupal_set_message(t('Subscription changes confirmed for %user.', array('%user' => $subscriber->getMail())));
+        drupal_set_message($this->t('Subscription changes confirmed for %user.', array('%user' => $subscriber->getMail())));
         return $this->redirect('<front>');
       }
     }
@@ -188,7 +188,7 @@ class ConfirmationController extends ControllerBase {
           if ($path = $config->get('subscription.confirm_unsubscribe_page')) {
             return $this->redirect(Url::fromUri("internal:/$path")->getRouteName());
           }
-          drupal_set_message(t('%user was unsubscribed from the %newsletter mailing list.', array('%user' => $subscriber->getMail(), '%newsletter' => $newsletter->name)));
+          drupal_set_message($this->t('%user was unsubscribed from the %newsletter mailing list.', array('%user' => $subscriber->getMail(), '%newsletter' => $newsletter->name)));
           return $this->redirect('<front>');
         }
         elseif ($action == 'add') {
@@ -196,7 +196,7 @@ class ConfirmationController extends ControllerBase {
           if ($path = $config->get('subscription.confirm_subscribe_page')) {
             return $this->redirect(Url::fromUri("internal:/$path")->getRouteName());
           }
-          drupal_set_message(t('%user was added to the %newsletter mailing list.', array('%user' => $subscriber->getMail(), '%newsletter' => $newsletter->name)));
+          drupal_set_message($this->t('%user was added to the %newsletter mailing list.', array('%user' => $subscriber->getMail(), '%newsletter' => $newsletter->name)));
           return $this->redirect('<front>');
         }
       }
diff --git a/src/Form/ConfirmAddForm.php b/src/Form/ConfirmAddForm.php
index dca6148..ea3dd67 100644
--- a/src/Form/ConfirmAddForm.php
+++ b/src/Form/ConfirmAddForm.php
@@ -16,21 +16,21 @@ class ConfirmAddForm extends ConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('Confirm subscription');
+    return $this->t('Confirm subscription');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getConfirmText() {
-    return t('Subscribe');
+    return $this->t('Subscribe');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getDescription() {
-    return t('You can always unsubscribe later.');
+    return $this->t('You can always unsubscribe later.');
   }
 
   /**
@@ -53,7 +53,7 @@ class ConfirmAddForm extends ConfirmFormBase {
   public function buildForm(array $form, FormStateInterface $form_state, $mail = '', NewsletterInterface $newsletter = NULL) {
     $form = parent::buildForm($form, $form_state);
     $form['question'] = array(
-      '#markup' => '<p>' . t('Are you sure you want to add %user to the %newsletter mailing list?', array('%user' => simplenews_mask_mail($mail), '%newsletter' => $newsletter->name)) . "<p>\n",
+      '#markup' => '<p>' . $this->t('Are you sure you want to add %user to the %newsletter mailing list?', array('%user' => simplenews_mask_mail($mail), '%newsletter' => $newsletter->name)) . "<p>\n",
     );
     $form['mail'] = array(
       '#type' => 'value',
@@ -83,7 +83,7 @@ class ConfirmAddForm extends ConfirmFormBase {
     if (!$path = $config->get('subscription.confirm_subscribe_page')) {
       $site_config = \Drupal::config('system.site');
       $path = $site_config->get('page.front');
-      drupal_set_message(t('%user was added to the %newsletter mailing list.', array('%user' => $form_state->getValue('mail'), '%newsletter' => $form_state->getValue('newsletter')->name)));
+      drupal_set_message($this->t('%user was added to the %newsletter mailing list.', array('%user' => $form_state->getValue('mail'), '%newsletter' => $form_state->getValue('newsletter')->name)));
     }
 
     $form_state->setRedirectUrl(Url::fromUri("internal:/$path"));
diff --git a/src/Form/ConfirmMultiForm.php b/src/Form/ConfirmMultiForm.php
index fdf8eb2..7820b4e 100644
--- a/src/Form/ConfirmMultiForm.php
+++ b/src/Form/ConfirmMultiForm.php
@@ -16,14 +16,14 @@ class ConfirmMultiForm extends ConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('Confirm subscription');
+    return $this->t('Confirm subscription');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getDescription() {
-    return t('You can always change your subscriptions later.');
+    return $this->t('You can always change your subscriptions later.');
   }
 
   /**
@@ -46,7 +46,7 @@ class ConfirmMultiForm extends ConfirmFormBase {
   public function buildForm(array $form, FormStateInterface $form_state, SubscriberInterface $subscriber = NULL) {
     $form = parent::buildForm($form, $form_state);
     $form['question'] = array(
-      '#markup' => '<p>' . t('Are you sure you want to confirm the following subscription changes for %user?', array('%user' => simplenews_mask_mail($subscriber->getMail()))) . "<p>\n",
+      '#markup' => '<p>' . $this->t('Are you sure you want to confirm the following subscription changes for %user?', array('%user' => simplenews_mask_mail($subscriber->getMail()))) . "<p>\n",
     );
 
     /** @var \Drupal\simplenews\Subscription\SubscriptionManagerInterface $subscription_manager */
@@ -96,7 +96,7 @@ class ConfirmMultiForm extends ConfirmFormBase {
     $subscriber->setChanges(array());
     $subscriber->save();
 
-    drupal_set_message(t('Subscription changes confirmed for %user.', array('%user' => $subscriber->getMail())));
+    drupal_set_message($this->t('Subscription changes confirmed for %user.', array('%user' => $subscriber->getMail())));
     $form_state->setRedirect('<front>');
   }
 
diff --git a/src/Form/ConfirmRemovalForm.php b/src/Form/ConfirmRemovalForm.php
index fcaf9ba..a83fcd5 100644
--- a/src/Form/ConfirmRemovalForm.php
+++ b/src/Form/ConfirmRemovalForm.php
@@ -16,21 +16,21 @@ class ConfirmRemovalForm extends ConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('Confirm remove subscription');
+    return $this->t('Confirm remove subscription');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getConfirmText() {
-    return t('Unsubscribe');
+    return $this->t('Unsubscribe');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getDescription() {
-    return t('This action will unsubscribe you from the newsletter mailing list.');
+    return $this->t('This action will unsubscribe you from the newsletter mailing list.');
   }
 
   /**
@@ -53,7 +53,7 @@ class ConfirmRemovalForm extends ConfirmFormBase {
   public function buildForm(array $form, FormStateInterface $form_state, $mail = '', NewsletterInterface $newsletter = NULL) {
     $form = parent::buildForm($form, $form_state);
     $form['question'] = array(
-      '#markup' => '<p>' . t('Are you sure you want to remove %user from the %newsletter mailing list?', array('%user' => simplenews_mask_mail($mail), '%newsletter' => $newsletter->name)) . "<p>\n",
+      '#markup' => '<p>' . $this->t('Are you sure you want to remove %user from the %newsletter mailing list?', array('%user' => simplenews_mask_mail($mail), '%newsletter' => $newsletter->name)) . "<p>\n",
     );
     $form['mail'] = array(
       '#type' => 'value',
@@ -83,7 +83,7 @@ class ConfirmRemovalForm extends ConfirmFormBase {
     if (!$path = $config->get('subscription.confirm_unsubscribe_page')) {
       $site_config = \Drupal::config('system.site');
       $path = $site_config->get('page.front');
-      drupal_set_message(t('%user was unsubscribed from the %newsletter mailing list.', array('%user' => $form_state->getValue('mail'), '%newsletter' => $form_state->getValue('newsletter')->name)));
+      drupal_set_message($this->t('%user was unsubscribed from the %newsletter mailing list.', array('%user' => $form_state->getValue('mail'), '%newsletter' => $form_state->getValue('newsletter')->name)));
     }
 
     $form_state->setRedirectUrl(Url::fromUri("internal:/$path"));
diff --git a/src/Form/NewsletterDeleteForm.php b/src/Form/NewsletterDeleteForm.php
index 0df6a64..96f7348 100644
--- a/src/Form/NewsletterDeleteForm.php
+++ b/src/Form/NewsletterDeleteForm.php
@@ -15,7 +15,7 @@ class NewsletterDeleteForm extends EntityConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
+    return $this->t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
   }
 
   /**
@@ -29,7 +29,7 @@ class NewsletterDeleteForm extends EntityConfirmFormBase {
    * {@inheritdoc}
    */
   public function getConfirmText() {
-    return t('Delete');
+    return $this->t('Delete');
   }
 
   /**
@@ -37,7 +37,7 @@ class NewsletterDeleteForm extends EntityConfirmFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $this->entity->delete();
-    drupal_set_message(t('Newsletter %label has been deleted.', array('%label' => $this->entity->label())));
+    drupal_set_message($this->t('Newsletter %label has been deleted.', array('%label' => $this->entity->label())));
     \Drupal::logger('simplenews')->notice('Newsletter %label has been deleted.', array('%label' => $this->entity->label()));
     $form_state->setRedirect('simplenews.newsletter_list');
   }
diff --git a/src/Form/NewsletterForm.php b/src/Form/NewsletterForm.php
index 1ab3161..83201e2 100644
--- a/src/Form/NewsletterForm.php
+++ b/src/Form/NewsletterForm.php
@@ -21,10 +21,10 @@ class NewsletterForm extends EntityForm {
 
     $form['name'] = array(
       '#type' => 'textfield',
-      '#title' => t('Name'),
+      '#title' => $this->t('Name'),
       '#maxlength' => 255,
       '#default_value' => $newsletter->label(),
-      '#description' => t("The newsletter name."),
+      '#description' => $this->t("The newsletter name."),
       '#required' => TRUE,
     );
     $form['id'] = array(
@@ -39,44 +39,44 @@ class NewsletterForm extends EntityForm {
     );
     $form['description'] = array(
       '#type' => 'textarea',
-      '#title' => t('Description'),
+      '#title' => $this->t('Description'),
       '#default_value' => $newsletter->description,
-      '#description' => t("A description of the newsletter."),
+      '#description' => $this->t("A description of the newsletter."),
     );
     $links = array(':mime_mail_url' => 'http://drupal.org/project/mimemail', ':html_url' => 'http://drupal.org/project/htmlmail');
-    $description = t('Newsletter format. Install <a href=":mime_mail_url">Mime Mail</a> module or <a href=":html_url">HTML Mail</a> module to send newsletters in HTML format.', $links);
+    $description = $this->t('Newsletter format. Install <a href=":mime_mail_url">Mime Mail</a> module or <a href=":html_url">HTML Mail</a> module to send newsletters in HTML format.', $links);
     $form['weight'] = array(
       '#type' => 'hidden',
       '#value' => $newsletter->weight,
      );
     $form['subscription'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Subscription settings'),
+      '#title' => $this->t('Subscription settings'),
       '#collapsible' => FALSE,
     );
   // Subscribe at account registration time.
   $options = simplenews_new_account_options();
   $form['subscription']['new_account'] = array(
     '#type' => 'select',
-    '#title' => t('Subscribe new account'),
+    '#title' => $this->t('Subscribe new account'),
     '#options' => $options,
     '#default_value' => $newsletter->new_account,
-    '#description' => t('None: This newsletter is not listed on the user registration page.<br />Default on: This newsletter is listed on the user registion page and is selected by default.<br />Default off: This newsletter is listed on the user registion page and is not selected by default.<br />Silent: A new user is automatically subscribed to this newsletter. The newsletter is not listed on the user registration page.'),
+    '#description' => $this->t('None: This newsletter is not listed on the user registration page.<br />Default on: This newsletter is listed on the user registion page and is selected by default.<br />Default off: This newsletter is listed on the user registion page and is not selected by default.<br />Silent: A new user is automatically subscribed to this newsletter. The newsletter is not listed on the user registration page.'),
     );
 
     // Type of (un)subsribe confirmation
     $options = simplenews_opt_inout_options();
     $form['subscription']['opt_inout'] = array(
       '#type' => 'select',
-      '#title' => t('Opt-in/out method'),
+      '#title' => $this->t('Opt-in/out method'),
       '#options' => $options,
       '#default_value' => $newsletter->opt_inout,
-      '#description' => t('Hidden: This newsletter does not appear on subscription forms. No unsubscription footer in newsletter.<br /> Single: Users are (un)subscribed immediately, no confirmation email is sent.<br />Double: When (un)subscribing at a subscription form, anonymous users receive an (un)subscription confirmation email. Authenticated users are (un)subscribed immediately.'),
+      '#description' => $this->t('Hidden: This newsletter does not appear on subscription forms. No unsubscription footer in newsletter.<br /> Single: Users are (un)subscribed immediately, no confirmation email is sent.<br />Double: When (un)subscribing at a subscription form, anonymous users receive an (un)subscription confirmation email. Authenticated users are (un)subscribed immediately.'),
     );
 
     $form['email'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Email settings'),
+      '#title' => $this->t('Email settings'),
       '#collapsible' => FALSE,
     );
     // Hide format selection if there is nothing to choose.
@@ -85,7 +85,7 @@ class NewsletterForm extends EntityForm {
     if (count($format_options) > 1) {
       $form['email']['format'] = array(
         '#type' => 'radios',
-        '#title' => t('Email format'),
+        '#title' => $this->t('Email format'),
         '#default_value' => $newsletter->format,
         '#options' => $format_options,
       );
@@ -96,14 +96,14 @@ class NewsletterForm extends EntityForm {
         '#value' => key($format_options),
       );
       $form['email']['format_text'] = array(
-        '#markup' => t('Newsletter emails will be sent in %format format.', array('%format' => $newsletter->format)),
+        '#markup' => $this->t('Newsletter emails will be sent in %format format.', array('%format' => $newsletter->format)),
       );
     }
     // Type of hyperlinks.
     $form['email']['hyperlinks'] = array(
       '#type' => 'radios',
-      '#title' => t('Hyperlink conversion'),
-      '#description' => t('Determine how the conversion to text is performed.'),
+      '#title' => $this->t('Hyperlink conversion'),
+      '#description' => $this->t('Determine how the conversion to text is performed.'),
       '#options' => array(t('Append hyperlinks as a numbered reference list'), t('Display hyperlinks inline with the text')),
       '#default_value' => $newsletter->hyperlinks,
       '#states' => array(
@@ -117,13 +117,13 @@ class NewsletterForm extends EntityForm {
 
     $form['email']['priority'] = array(
       '#type' => 'select',
-      '#title' => t('Email priority'),
+      '#title' => $this->t('Email priority'),
       '#default_value' => $newsletter->priority,
       '#options' => simplenews_get_priority(),
     );
     $form['email']['receipt'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Request receipt'),
+      '#title' => $this->t('Request receipt'),
       '#return_value' => 1,
       '#default_value' => $newsletter->receipt,
     );
@@ -131,12 +131,12 @@ class NewsletterForm extends EntityForm {
     // Email sender name
     $form['simplenews_sender_information'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Sender information'),
+      '#title' => $this->t('Sender information'),
       '#collapsible' => FALSE,
     );
     $form['simplenews_sender_information']['from_name'] = array(
       '#type' => 'textfield',
-      '#title' => t('From name'),
+      '#title' => $this->t('From name'),
       '#size' => 60,
       '#maxlength' => 128,
       '#default_value' => $newsletter->from_name,
@@ -145,13 +145,13 @@ class NewsletterForm extends EntityForm {
     // Email subject
     $form['simplenews_subject'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Newsletter subject'),
+      '#title' => $this->t('Newsletter subject'),
       '#collapsible' => FALSE,
     );
 
     $form['simplenews_subject']['subject'] = array(
       '#type' => 'textfield',
-      '#title' => t('Email subject'),
+      '#title' => $this->t('Email subject'),
       '#size' => 60,
       '#maxlength' => 128,
       '#required' => TRUE,
@@ -168,7 +168,7 @@ class NewsletterForm extends EntityForm {
     // Email from address
     $form['simplenews_sender_information']['from_address'] = array(
       '#type' => 'email',
-      '#title' => t('From email address'),
+      '#title' => $this->t('From email address'),
       '#size' => 60,
       '#maxlength' => 128,
       '#required' => TRUE,
@@ -178,14 +178,14 @@ class NewsletterForm extends EntityForm {
     $form['actions'] = array('#type' => 'actions');
     $form['actions']['submit'] = array(
       '#type' => 'submit',
-      '#value' => t('Save'),
+      '#value' => $this->t('Save'),
       '#weight' => 50,
     );
 
     if ($newsletter->id) {
       $form['actions']['delete'] = array(
         '#type' => 'submit',
-        '#value' => t('Delete'),
+        '#value' => $this->t('Delete'),
         '#weight' => 55,
       );
     }
@@ -202,11 +202,11 @@ class NewsletterForm extends EntityForm {
     $edit_link = \Drupal::linkGenerator()->generate($this->t('Edit'), $this->entity->urlInfo());
 
     if ($status == SAVED_UPDATED) {
-      drupal_set_message(t('Newsletter %label has been updated.', array('%label' => $newsletter->label())));
+      drupal_set_message($this->t('Newsletter %label has been updated.', array('%label' => $newsletter->label())));
       \Drupal::logger('simplenews')->notice('Newsletter %label has been updated.', array('%label' => $newsletter->label(), 'link' => $edit_link));
     }
     else {
-      drupal_set_message(t('Newsletter %label has been added.', array('%label' => $newsletter->label())));
+      drupal_set_message($this->t('Newsletter %label has been added.', array('%label' => $newsletter->label())));
       \Drupal::logger('simplenews')->notice('Newsletter %label has been added.', array('%label' => $newsletter->label(), 'link' => $edit_link));
     }
 
diff --git a/src/Form/NodeTabForm.php b/src/Form/NodeTabForm.php
index 8772b7f..1759e67 100644
--- a/src/Form/NodeTabForm.php
+++ b/src/Form/NodeTabForm.php
@@ -28,7 +28,7 @@ class NodeTabForm extends FormBase {
     $subscriber_count = simplenews_count_subscriptions($node->simplenews_issue->target_id);
     $status = $node->simplenews_issue->status;
 
-    $form['#title'] = t('<em>Newsletter issue</em> @title', array('@title' => $node->getTitle()));
+    $form['#title'] = $this->t('<em>Newsletter issue</em> @title', array('@title' => $node->getTitle()));
 
     // We will need the node.
     $form_state->set('node', $node);
@@ -40,12 +40,12 @@ class NodeTabForm extends FormBase {
       $form['test'] = array(
         '#type' => 'details',
         '#open' => TRUE,
-        '#title' => t('Test'),
+        '#title' => $this->t('Test'),
       );
       $form['test']['test_address'] = array(
         '#type' => 'textfield',
-        '#title' => t('Test email addresses'),
-        '#description' => t('A comma-separated list of email addresses to be used as test addresses.'),
+        '#title' => $this->t('Test email addresses'),
+        '#description' => $this->t('A comma-separated list of email addresses to be used as test addresses.'),
         '#default_value' => \Drupal::currentUser()->getEmail(),
         '#size' => 60,
         '#maxlength' => 128,
@@ -53,7 +53,7 @@ class NodeTabForm extends FormBase {
 
       $form['test']['submit'] = array(
         '#type' => 'submit',
-        '#value' => t('Send test newsletter issue'),
+        '#value' => $this->t('Send test newsletter issue'),
         '#name' => 'send_test',
         '#submit' => array('::submitTestMail'),
         '#validate' => array('::validateTestAddress'),
@@ -61,7 +61,7 @@ class NodeTabForm extends FormBase {
       $form['send'] = array(
         '#type' => 'details',
         '#open' => TRUE,
-        '#title' => t('Send'),
+        '#title' => $this->t('Send'),
       );
       $default_handler = isset($form_state->getValue('simplenews')['recipient_handler']) ? $form_state->getValue('simplenews')['recipient_handler'] : $node->simplenews_issue->handler;
 
@@ -69,8 +69,8 @@ class NodeTabForm extends FormBase {
       $options = $recipient_handler_manager->getOptions();
       $form['send']['recipient_handler'] = array(
         '#type' => 'select',
-        '#title' => t('Recipients'),
-        '#description' => t('Please select to configure who to send the email to.'),
+        '#title' => $this->t('Recipients'),
+        '#description' => $this->t('Please select to configure who to send the email to.'),
         '#options' => $options,
         '#default_value' => $default_handler,
         '#access' => count($options) > 1,
@@ -105,13 +105,13 @@ class NodeTabForm extends FormBase {
       // Add some text to describe the send situation.
       $form['send']['count'] = array(
         '#type' => 'item',
-        '#markup' => t('Send newsletter issue to @count subscribers.', array('@count' => $subscriber_count)),
+        '#markup' => $this->t('Send newsletter issue to @count subscribers.', array('@count' => $subscriber_count)),
       );
       if (!$config->get('mail.use_cron')) {
-        $send_text = t('Mails will be sent immediately.');
+        $send_text = $this->t('Mails will be sent immediately.');
       }
       else {
-        $send_text = t('Mails will be sent when cron runs.');
+        $send_text = $this->t('Mails will be sent when cron runs.');
       }
 
       $form['send']['method'] = array(
@@ -122,7 +122,7 @@ class NodeTabForm extends FormBase {
         $form['send']['send_now'] = array(
           '#type' => 'submit',
           '#button_type' => 'primary',
-          '#value' => t('Send now'),
+          '#value' => $this->t('Send now'),
           '#submit' => array('::submitForm', '::submitSendNow'),
         );
       }
@@ -130,7 +130,7 @@ class NodeTabForm extends FormBase {
         $form['send']['send_on_publish'] = array(
           '#type' => 'submit',
           '#button_type' => 'primary',
-          '#value' => t('Send on publish'),
+          '#value' => $this->t('Send on publish'),
           '#submit' => array('::submitForm', '::submitSendLater'),
         );
       }
@@ -140,14 +140,14 @@ class NodeTabForm extends FormBase {
         '#type' => 'item',
       );
       if ($status == SIMPLENEWS_STATUS_SEND_READY) {
-        $form['status']['#title'] = t('This newsletter issue has been sent to @count subscribers', array('@count' => $node->simplenews_issue->sent_count));
+        $form['status']['#title'] = $this->t('This newsletter issue has been sent to @count subscribers', array('@count' => $node->simplenews_issue->sent_count));
       }
       else {
         if ($status == SIMPLENEWS_STATUS_SEND_PUBLISH) {
-          $form['status']['#title'] = t('The newsletter issue will be sent when the content is published.');
+          $form['status']['#title'] = $this->t('The newsletter issue will be sent when the content is published.');
         }
         else {
-          $form['status']['#title'] = t('This newsletter issue is pending, @count of @total mails already sent.', array('@count' => (int) $node->simplenews_issue->sent_count, '@total' => \Drupal::service('simplenews.spool_storage')->countMails(['entity_type' => 'node', 'entity_id' => $node->id()])));
+          $form['status']['#title'] = $this->t('This newsletter issue is pending, @count of @total mails already sent.', array('@count' => (int) $node->simplenews_issue->sent_count, '@total' => \Drupal::service('simplenews.spool_storage')->countMails(['entity_type' => 'node', 'entity_id' => $node->id()])));
         }
         $form['actions'] = array(
           '#type' => 'actions',
@@ -155,7 +155,7 @@ class NodeTabForm extends FormBase {
         $form['actions']['stop'] = array(
           '#type' => 'submit',
           '#submit' => array('::submitStop'),
-          '#value' => t('Stop sending'),
+          '#value' => $this->t('Stop sending'),
         );
       }
     }
@@ -253,10 +253,10 @@ class NodeTabForm extends FormBase {
     \Drupal::service('simplenews.spool_storage')->addFromEntity($node);
     // Attempt to send immediatly, if configured to do so.
     if (\Drupal::service('simplenews.mailer')->attemptImmediateSend(array('entity_id' => $node->id(), 'entity_type' => 'node'))) {
-      drupal_set_message(t('Newsletter %title sent.', array('%title' => $node->getTitle())));
+      drupal_set_message($this->t('Newsletter %title sent.', array('%title' => $node->getTitle())));
     }
     else {
-      drupal_set_message(t('Newsletter issue %title pending.', array('%title' => $node->getTitle())));
+      drupal_set_message($this->t('Newsletter issue %title pending.', array('%title' => $node->getTitle())));
     }
     $node->save();
   }
@@ -271,7 +271,7 @@ class NodeTabForm extends FormBase {
     $node = $form_state->get('node');
     // Set the node to pending status.
     $node->simplenews_issue->status = SIMPLENEWS_STATUS_SEND_PUBLISH;
-    drupal_set_message(t('Newsletter issue %title will be sent when published.', array('%title' => $node->getTitle())));
+    drupal_set_message($this->t('Newsletter issue %title will be sent when published.', array('%title' => $node->getTitle())));
     $node->save();
   }
 
@@ -289,7 +289,7 @@ class NodeTabForm extends FormBase {
 
     $node->save();
 
-    drupal_set_message(t('Sending of %title was stopped. @count pending email(s) were deleted.', array(
+    drupal_set_message($this->t('Sending of %title was stopped. @count pending email(s) were deleted.', array(
       '%title' => $node->getTitle(),
       '@count' => $count,
     )));
diff --git a/src/Form/RequestHashForm.php b/src/Form/RequestHashForm.php
index 8432aac..94dec49 100644
--- a/src/Form/RequestHashForm.php
+++ b/src/Form/RequestHashForm.php
@@ -15,7 +15,7 @@ class RequestHashForm extends ConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('This link has expired.');
+    return $this->t('This link has expired.');
   }
 
   /**
@@ -29,7 +29,7 @@ class RequestHashForm extends ConfirmFormBase {
    * {@inheritdoc}
    */
   public function getConfirmText() {
-    return t('Request new confirmation mail');
+    return $this->t('Request new confirmation mail');
   }
 
   /**
@@ -78,7 +78,7 @@ class RequestHashForm extends ConfirmFormBase {
     $params['context'] = $form_state->get('context');
     $subscriber = $params['context']['simplenews_subscriber'];
     \Drupal::service('plugin.manager.mail')->mail('simplenews', $form_state->get('key'), $subscriber->getMail(), $subscriber->getLangcode(), $params, $params['from']['address']);
-    drupal_set_message(t('The confirmation mail has been sent.'));
+    drupal_set_message($this->t('The confirmation mail has been sent.'));
     $form_state->setRedirect('<front>');
   }
 
diff --git a/src/Form/SubscriberDeleteForm.php b/src/Form/SubscriberDeleteForm.php
index 6835cfb..d8e7951 100644
--- a/src/Form/SubscriberDeleteForm.php
+++ b/src/Form/SubscriberDeleteForm.php
@@ -15,7 +15,7 @@ class SubscriberDeleteForm extends ContentEntityConfirmFormBase {
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
+    return $this->t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
   }
 
   /**
@@ -29,7 +29,7 @@ class SubscriberDeleteForm extends ContentEntityConfirmFormBase {
    * {@inheritdoc}
    */
   public function getConfirmText() {
-    return t('Delete');
+    return $this->t('Delete');
   }
 
   /**
@@ -37,7 +37,7 @@ class SubscriberDeleteForm extends ContentEntityConfirmFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $this->entity->delete();
-    drupal_set_message(t('Subscriber %label has been deleted.', array('%label' => $this->entity->label())));
+    drupal_set_message($this->t('Subscriber %label has been deleted.', array('%label' => $this->entity->label())));
     \Drupal::logger('simplenews')->notice('Subscriber %label has been deleted.', array('%label' => $this->entity->label()));
     $form_state->setRedirect('view.simplenews_subscribers.page_1');
   }
diff --git a/src/Form/SubscriberExportForm.php b/src/Form/SubscriberExportForm.php
index 85c7ddd..b624547 100644
--- a/src/Form/SubscriberExportForm.php
+++ b/src/Form/SubscriberExportForm.php
@@ -56,7 +56,7 @@ class SubscriberExportForm extends FormBase {
     if ($mails) {
       return implode(", ", $mails);
     }
-    return t('No addresses were found.');
+    return $this->t('No addresses were found.');
   }
 
   /**
@@ -70,36 +70,36 @@ class SubscriberExportForm extends FormBase {
 
     $form['states'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Status'),
+      '#title' => $this->t('Status'),
       '#options' => array(
         'active' => t('Active users'),
         'inactive' => t('Inactive users'),
       ),
       '#default_value' => $default['states'],
-      '#description' => t('Subscriptions matching the selected states will be exported.'),
+      '#description' => $this->t('Subscriptions matching the selected states will be exported.'),
       '#required' => TRUE,
     );
 
     $form['subscribed'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Subscribed'),
+      '#title' => $this->t('Subscribed'),
       '#options' => array(
         'subscribed' => t('Subscribed to the newsletter'),
         'unconfirmed' => t('Unconfirmed to the newsletter'),
         'unsubscribed' => t('Unsubscribed from the newsletter'),
       ),
       '#default_value' => $default['subscribed'],
-      '#description' => t('Subscriptions matching the selected subscription states will be exported.'),
+      '#description' => $this->t('Subscriptions matching the selected subscription states will be exported.'),
       '#required' => TRUE,
     );
 
     $options = simplenews_newsletter_list();
     $form['newsletters'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Newsletter'),
+      '#title' => $this->t('Newsletter'),
       '#options' => $options,
       '#default_value' => $default['newsletters'],
-      '#description' => t('Subscriptions matching the selected newsletters will be exported.'),
+      '#description' => $this->t('Subscriptions matching the selected newsletters will be exported.'),
       '#required' => TRUE,
     );
 
@@ -109,7 +109,7 @@ class SubscriberExportForm extends FormBase {
     if (isset($_GET['states']) && empty($input)) {
       $form['emails'] = array(
         '#type' => 'textarea',
-        '#title' => t('Export results'),
+        '#title' => $this->t('Export results'),
         '#cols' => 60,
         '#rows' => 5,
         '#value' => $this->getEmails($_GET['states'], $_GET['subscribed'], $_GET['newsletters']),
@@ -118,7 +118,7 @@ class SubscriberExportForm extends FormBase {
 
     $form['submit'] = array(
       '#type' => 'submit',
-      '#value' => t('Export'),
+      '#value' => $this->t('Export'),
     );
     return $form;
   }
diff --git a/src/Form/SubscriberForm.php b/src/Form/SubscriberForm.php
index 4042ed2..6d606d6 100644
--- a/src/Form/SubscriberForm.php
+++ b/src/Form/SubscriberForm.php
@@ -26,14 +26,14 @@ class SubscriberForm extends ContentEntityForm {
     $form['#title'] = $this->t('Edit subscriber @mail', array('@mail' => $subscriber->getMail()));
 
     $form['activated'] = array(
-      '#title' => t('Status'),
+      '#title' => $this->t('Status'),
       '#type' => 'fieldset',
-      '#description' => t('Active or inactive account.'),
+      '#description' => $this->t('Active or inactive account.'),
       '#weight' => 15,
     );
     $form['activated']['status'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Active'),
+      '#title' => $this->t('Active'),
       '#default_value' => $subscriber->getStatus(),
     );
 
@@ -45,15 +45,15 @@ class SubscriberForm extends ContentEntityForm {
       }
       $form['language'] = array(
         '#type' => 'fieldset',
-        '#title' => t('Preferred language'),
-        '#description' => t('The e-mails will be localized in language chosen. Real users have their preference in account settings.'),
+        '#title' => $this->t('Preferred language'),
+        '#description' => $this->t('The e-mails will be localized in language chosen. Real users have their preference in account settings.'),
         '#disabled' => FALSE,
       );
       if ($subscriber->getUserId()) {
         // Fallback if user has not defined a language.
         $form['language']['langcode'] = array(
           '#type' => 'item',
-          '#title' => t('User language'),
+          '#title' => $this->t('User language'),
           '#markup' => $subscriber->language()->getName(),
         );
       }
diff --git a/src/Form/SubscriberMassSubscribeForm.php b/src/Form/SubscriberMassSubscribeForm.php
index 2a41b34..5a83ea8 100644
--- a/src/Form/SubscriberMassSubscribeForm.php
+++ b/src/Form/SubscriberMassSubscribeForm.php
@@ -24,15 +24,15 @@ class SubscriberMassSubscribeForm extends FormBase {
   public function buildForm(array $form, FormStateInterface $form_state) {
     $form['emails'] = array(
       '#type' => 'textarea',
-      '#title' => t('Email addresses'),
+      '#title' => $this->t('Email addresses'),
       '#cols' => 60,
       '#rows' => 5,
-      '#description' => t('Email addresses must be separated by comma, space or newline.'),
+      '#description' => $this->t('Email addresses must be separated by comma, space or newline.'),
     );
 
     $form['newsletters'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Subscribe to'),
+      '#title' => $this->t('Subscribe to'),
       '#options' => simplenews_newsletter_list(),
       '#required' => TRUE,
     );
@@ -43,25 +43,25 @@ class SubscriberMassSubscribeForm extends FormBase {
 
     $form['resubscribe'] = array(
       '#type' => 'checkbox',
-      '#title' => t('Force resubscription'),
-      '#description' => t('If checked, previously unsubscribed e-mail addresses will be resubscribed. Consider that this might be against the will of your users.'),
+      '#title' => $this->t('Force resubscription'),
+      '#description' => $this->t('If checked, previously unsubscribed e-mail addresses will be resubscribed. Consider that this might be against the will of your users.'),
     );
 
     // Include language selection when the site is multilingual.
     // Default value is the empty string which will result in receiving emails
     // in the site's default language.
     if (\Drupal::languageManager()->isMultilingual()) {
-      $options[''] = t('Site default language');
+      $options[''] = $this->t('Site default language');
       $languages = \Drupal::languageManager()->getLanguages();
       foreach ($languages as $langcode => $language) {
         $options[$langcode] = $language->getName();
       }
       $form['language'] = array(
         '#type' => 'radios',
-        '#title' => t('Anonymous user preferred language'),
+        '#title' => $this->t('Anonymous user preferred language'),
         '#default_value' => '',
         '#options' => $options,
-        '#description' => t('New subscriptions will be subscribed with the selected preferred language. The language of existing subscribers is unchanged.'),
+        '#description' => $this->t('New subscriptions will be subscribed with the selected preferred language. The language of existing subscribers is unchanged.'),
       );
     }
     else {
@@ -73,7 +73,7 @@ class SubscriberMassSubscribeForm extends FormBase {
 
     $form['submit'] = array(
       '#type' => 'submit',
-      '#value' => t('Subscribe'),
+      '#value' => $this->t('Subscribe'),
     );
 
     return $form;
@@ -128,29 +128,29 @@ class SubscriberMassSubscribeForm extends FormBase {
     }
     if ($added) {
       $added = implode(", ", $added);
-      drupal_set_message(t('The following addresses were added or updated: %added.', array('%added' => $added)));
+      drupal_set_message($this->t('The following addresses were added or updated: %added.', array('%added' => $added)));
 
       $list_names = array();
       foreach (simplenews_newsletter_load_multiple($checked_newsletters) as $newsletter) {
         $list_names[] = $newsletter->label();
       }
-      drupal_set_message(t('The addresses were subscribed to the following newsletters: %newsletters.', array('%newsletters' => implode(', ', $list_names))));
+      drupal_set_message($this->t('The addresses were subscribed to the following newsletters: %newsletters.', array('%newsletters' => implode(', ', $list_names))));
     }
     else {
-      drupal_set_message(t('No addresses were added.'));
+      drupal_set_message($this->t('No addresses were added.'));
     }
     if ($invalid) {
       $invalid = implode(", ", $invalid);
-      drupal_set_message(t('The following addresses were invalid: %invalid.', array('%invalid' => $invalid)), 'error');
+      drupal_set_message($this->t('The following addresses were invalid: %invalid.', array('%invalid' => $invalid)), 'error');
     }
 
     foreach ($unsubscribed as $name => $subscribers) {
       $subscribers = implode(", ", $subscribers);
-      drupal_set_message(t('The following addresses were skipped because they have previously unsubscribed from %name: %unsubscribed.', array('%name' => $name, '%unsubscribed' => $subscribers)), 'warning');
+      drupal_set_message($this->t('The following addresses were skipped because they have previously unsubscribed from %name: %unsubscribed.', array('%name' => $name, '%unsubscribed' => $subscribers)), 'warning');
     }
 
     if (!empty($unsubscribed)) {
-      drupal_set_message(t("If you would like to resubscribe them, use the 'Force resubscription' option."), 'warning');
+      drupal_set_message($this->t("If you would like to resubscribe them, use the 'Force resubscription' option."), 'warning');
     }
 
     // Return to the parent page.
diff --git a/src/Form/SubscriberMassUnsubscribeForm.php b/src/Form/SubscriberMassUnsubscribeForm.php
index 4bad415..e07d6c6 100644
--- a/src/Form/SubscriberMassUnsubscribeForm.php
+++ b/src/Form/SubscriberMassUnsubscribeForm.php
@@ -24,15 +24,15 @@ class SubscriberMassUnsubscribeForm extends FormBase {
   public function buildForm(array $form, FormStateInterface $form_state) {
     $form['emails'] = array(
       '#type' => 'textarea',
-      '#title' => t('Email addresses'),
+      '#title' => $this->t('Email addresses'),
       '#cols' => 60,
       '#rows' => 5,
-      '#description' => t('Email addresses must be separated by comma, space or newline.'),
+      '#description' => $this->t('Email addresses must be separated by comma, space or newline.'),
     );
 
     $form['newsletters'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Unsubscribe from'),
+      '#title' => $this->t('Unsubscribe from'),
       '#options' => simplenews_newsletter_list(),
       '#required' => TRUE,
     );
@@ -43,7 +43,7 @@ class SubscriberMassUnsubscribeForm extends FormBase {
 
     $form['submit'] = array(
       '#type' => 'submit',
-      '#value' => t('Unsubscribe'),
+      '#value' => $this->t('Unsubscribe'),
     );
     return $form;
   }
@@ -80,21 +80,21 @@ class SubscriberMassUnsubscribeForm extends FormBase {
     }
     if ($removed) {
       $removed = implode(", ", $removed);
-      drupal_set_message(t('The following addresses were unsubscribed: %removed.', array('%removed' => $removed)));
+      drupal_set_message($this->t('The following addresses were unsubscribed: %removed.', array('%removed' => $removed)));
 
       $newsletters = simplenews_newsletter_get_all();
       $list_names = array();
       foreach ($checked_lists as $newsletter_id) {
         $list_names[] = $newsletters[$newsletter_id]->label();
       }
-      drupal_set_message(t('The addresses were unsubscribed from the following newsletters: %newsletters.', array('%newsletters' => implode(', ', $list_names))));
+      drupal_set_message($this->t('The addresses were unsubscribed from the following newsletters: %newsletters.', array('%newsletters' => implode(', ', $list_names))));
     }
     else {
-      drupal_set_message(t('No addresses were removed.'));
+      drupal_set_message($this->t('No addresses were removed.'));
     }
     if ($invalid) {
       $invalid = implode(", ", $invalid);
-      drupal_set_message(t('The following addresses were invalid: %invalid.', array('%invalid' => $invalid)), 'error');
+      drupal_set_message($this->t('The following addresses were invalid: %invalid.', array('%invalid' => $invalid)), 'error');
     }
 
     // Return to the parent page.
diff --git a/src/Form/SubscriptionsFormBase.php b/src/Form/SubscriptionsFormBase.php
index 66fc731..4cfab59 100644
--- a/src/Form/SubscriptionsFormBase.php
+++ b/src/Form/SubscriptionsFormBase.php
@@ -133,12 +133,12 @@ abstract class SubscriptionsFormBase extends ContentEntityForm {
     // Modify UI texts.
     if ($mail = $this->entity->getMail()) {
       $form['mail']['#access'] = FALSE;
-      $form['subscriptions']['widget']['#title'] = t('Subscriptions for %mail', array('%mail' => $mail));
-      $form['subscriptions']['widget']['#description'] = t('Check the newsletters you want to subscribe to. Uncheck the ones you want to unsubscribe from.');
+      $form['subscriptions']['widget']['#title'] = $this->t('Subscriptions for %mail', array('%mail' => $mail));
+      $form['subscriptions']['widget']['#description'] = $this->t('Check the newsletters you want to subscribe to. Uncheck the ones you want to unsubscribe from.');
     }
     else {
-      $form['subscriptions']['widget']['#title'] = t('Manage your newsletter subscriptions');
-      $form['subscriptions']['widget']['#description'] = t('Select the newsletter(s) to which you want to subscribe or unsubscribe.');
+      $form['subscriptions']['widget']['#title'] = $this->t('Manage your newsletter subscriptions');
+      $form['subscriptions']['widget']['#description'] = $this->t('Select the newsletter(s) to which you want to subscribe or unsubscribe.');
     }
 
     return $form;
diff --git a/src/NewsletterListBuilder.php b/src/NewsletterListBuilder.php
index 3dda21d..77850d0 100644
--- a/src/NewsletterListBuilder.php
+++ b/src/NewsletterListBuilder.php
@@ -15,7 +15,7 @@ class NewsletterListBuilder extends ConfigEntityListBuilder {
    * {@inheritdoc}
    */
   public function buildHeader() {
-    $header['name'] = t('Newsletter name');
+    $header['name'] = $this->t('Newsletter name');
     return $header + parent::buildHeader();
   }
 
diff --git a/src/Plugin/Action/SendIssue.php b/src/Plugin/Action/SendIssue.php
index 1daef79..2665f70 100644
--- a/src/Plugin/Action/SendIssue.php
+++ b/src/Plugin/Action/SendIssue.php
@@ -29,7 +29,7 @@ class SendIssue extends ActionBase {
       }
       if (!$node->isPublished()) {
         simplenews_issue_update_sent_status($node, SIMPLENEWS_COMMAND_SEND_PUBLISH);
-        drupal_set_message(t('Newsletter issue %title is unpublished and will be sent on publish.', array('%title' => $node->label())));
+        drupal_set_message($this->t('Newsletter issue %title is unpublished and will be sent on publish.', array('%title' => $node->label())));
         continue;
       }
       \Drupal::service('simplenews.spool_storage')->addFromEntity($node);
@@ -41,11 +41,11 @@ class SendIssue extends ActionBase {
       $conditions = array('entity_id' => array_keys($nodes), 'entity_type' => 'node');
       // Attempt to send immediatly, if configured to do so.
       if (\Drupal::service('simplenews.mailer')->attemptImmediateSend($conditions)) {
-        drupal_set_message(t('Sent the following newsletter(s): %titles.', array('%titles' => implode(', ', $labels))));
+        drupal_set_message($this->t('Sent the following newsletter(s): %titles.', array('%titles' => implode(', ', $labels))));
         $status = SIMPLENEWS_STATUS_SEND_READY;
       }
       else {
-        drupal_set_message(t('The following newsletter(s) are now pending: %titles.', array('%titles' => implode(', ', $labels))));
+        drupal_set_message($this->t('The following newsletter(s) are now pending: %titles.', array('%titles' => implode(', ', $labels))));
         $status = SIMPLENEWS_STATUS_SEND_PENDING;
       }
       foreach ($nodes as $node) {
diff --git a/src/Plugin/Action/StopIssue.php b/src/Plugin/Action/StopIssue.php
index 210c2e9..e75e92d 100644
--- a/src/Plugin/Action/StopIssue.php
+++ b/src/Plugin/Action/StopIssue.php
@@ -28,7 +28,7 @@ class StopIssue extends ActionBase {
         // Set newsletter issue to not sent yet.
         $node->simplenews_issue->status = SIMPLENEWS_STATUS_SEND_NOT;
         $node->save();
-        drupal_set_message(t('Sending of %title was stopped. @count pending email(s) were deleted.', array(
+        drupal_set_message($this->t('Sending of %title was stopped. @count pending email(s) were deleted.', array(
           '%title' => $node->getTitle(),
           '@count' => $count,
         )));
diff --git a/src/Plugin/Block/SimplenewsSubscriptionBlock.php b/src/Plugin/Block/SimplenewsSubscriptionBlock.php
index 45a073e..97d6212 100644
--- a/src/Plugin/Block/SimplenewsSubscriptionBlock.php
+++ b/src/Plugin/Block/SimplenewsSubscriptionBlock.php
@@ -103,24 +103,24 @@ class SimplenewsSubscriptionBlock extends BlockBase implements ContainerFactoryP
 
     $form['newsletters'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Newsletters'),
+      '#title' => $this->t('Newsletters'),
       '#options' => $options,
       '#required' => TRUE,
       '#default_value' => $this->configuration['newsletters'],
     );
     $form['message'] = array(
       '#type' => 'textfield',
-      '#title' => t('Block message'),
+      '#title' => $this->t('Block message'),
       '#size' => 60,
       '#maxlength' => 255,
       '#default_value' => $this->configuration['message'],
     );
     $form['unique_id'] = array(
       '#type' => 'textfield',
-      '#title' => t('Unique ID'),
+      '#title' => $this->t('Unique ID'),
       '#size' => 60,
       '#maxlength' => 255,
-      '#description' => t('Each subscription block must have a unique form ID. If no value is provided, a random ID will be generated. Use this to have a predictable, short ID, e.g. to configure this form use a CAPTCHA.'),
+      '#description' => $this->t('Each subscription block must have a unique form ID. If no value is provided, a random ID will be generated. Use this to have a predictable, short ID, e.g. to configure this form use a CAPTCHA.'),
       '#default_value' => $this->configuration['unique_id'],
     );
     /*if (\Drupal::moduleHandler()->moduleExists('views')) {
diff --git a/src/Plugin/views/field/SendStatus.php b/src/Plugin/views/field/SendStatus.php
index b7f4787..443ea01 100644
--- a/src/Plugin/views/field/SendStatus.php
+++ b/src/Plugin/views/field/SendStatus.php
@@ -62,21 +62,21 @@ class SendStatus extends FieldPluginBase {
       SIMPLENEWS_STATUS_SEND_READY => 'images/sn-sent.png',
     );
     if ($status == SIMPLENEWS_STATUS_SEND_READY) {
-      $message['description'] = t('Newsletter issue sent to @sent_count subscribers.', ['@sent_count' => $sent_count]);
+      $message['description'] = $this->t('Newsletter issue sent to @sent_count subscribers.', ['@sent_count' => $sent_count]);
       $message['uri'] = drupal_get_path('module', 'simplenews') . '/' . $images[$status];
     }
     elseif ($status == SIMPLENEWS_STATUS_SEND_PENDING) {
-      $message['description'] = t('Newsletter issue is pending, @sent_count mails sent out of @count.', array(
+      $message['description'] = $this->t('Newsletter issue is pending, @sent_count mails sent out of @count.', array(
         '@sent_count' => $sent_count,
         '@count' => $subscriber_count
       ));
       $message['uri'] = drupal_get_path('module', 'simplenews') . '/' . $images[$status];
     }
     elseif (($status == SIMPLENEWS_STATUS_SEND_NOT)) {
-      $message['description'] = t('Newsletter issue will be sent to @count subscribers.', array('@count' => $subscriber_count));
+      $message['description'] = $this->t('Newsletter issue will be sent to @count subscribers.', array('@count' => $subscriber_count));
     }
     if (!$published) {
-      $message['description'] = t('Newsletter issue will be sent to @count subscribers on publish.', array('@count' => $subscriber_count));
+      $message['description'] = $this->t('Newsletter issue will be sent to @count subscribers on publish.', array('@count' => $subscriber_count));
     }
     return $message;
   }