diff --git a/core/modules/contact/contact.module b/core/modules/contact/contact.module
index 1f479f2..b4faa7d 100644
--- a/core/modules/contact/contact.module
+++ b/core/modules/contact/contact.module
@@ -122,17 +122,17 @@ function contact_mail($key, &$message, $params) {
   $language = \Drupal::languageManager()->getLanguage($message['langcode']);
 
   $variables = array(
-    '!site-name' => \Drupal::config('system.site')->get('name'),
-    '!subject' => $contact_message->getSubject(),
-    '!form' => !empty($params['contact_form']) ? $params['contact_form']->label() : NULL,
-    '!form-url' => \Drupal::url('<current>', [], ['absolute' => TRUE, 'language' => $language]),
-    '!sender-name' => user_format_name($sender),
+    '@site-name' => \Drupal::config('system.site')->get('name'),
+    '@subject' => $contact_message->getSubject(),
+    '@form' => !empty($params['contact_form']) ? $params['contact_form']->label() : NULL,
+    '@form-url' => \Drupal::url('<current>', [], ['absolute' => TRUE, 'language' => $language]),
+    '@sender-name' => user_format_name($sender),
   );
   if ($sender->isAuthenticated()) {
-    $variables['!sender-url'] = $sender->url('canonical', array('absolute' => TRUE, 'language' => $language));
+    $variables['@sender-url'] = $sender->url('canonical', array('absolute' => TRUE, 'language' => $language));
   }
   else {
-    $variables['!sender-url'] = $params['sender']->getEmail();
+    $variables['@sender-url'] = $params['sender']->getEmail();
   }
 
   $options = array('langcode' => $language->getId());
@@ -140,27 +140,27 @@ function contact_mail($key, &$message, $params) {
   switch ($key) {
     case 'page_mail':
     case 'page_copy':
-      $message['subject'] .= t('[!form] !subject', $variables, $options);
-      $message['body'][] = t("!sender-name (!sender-url) sent a message using the contact form at !form-url.", $variables, $options);
+      $message['subject'] .= t('[@form] @subject', $variables, $options);
+      $message['body'][] = t("@sender-name (@sender-url) sent a message using the contact form at @form-url.", $variables, $options);
       $build = entity_view($contact_message, 'mail', $language->getId());
       $message['body'][] = (string) \Drupal::service('renderer')->renderPlain($build);
       break;
 
     case 'page_autoreply':
-      $message['subject'] .= t('[!form] !subject', $variables, $options);
+      $message['subject'] .= t('[@form] @subject', $variables, $options);
       $message['body'][] = $params['contact_form']->getReply();
       break;
 
     case 'user_mail':
     case 'user_copy':
       $variables += array(
-        '!recipient-name' => user_format_name($params['recipient']),
-        '!recipient-edit-url' => $params['recipient']->url('edit-form', array('absolute' => TRUE, 'language' => $language)),
+        '@recipient-name' => user_format_name($params['recipient']),
+        '@recipient-edit-url' => $params['recipient']->url('edit-form', array('absolute' => TRUE, 'language' => $language)),
       );
-      $message['subject'] .= t('[!site-name] !subject', $variables, $options);
-      $message['body'][] = t('Hello !recipient-name,', $variables, $options);
-      $message['body'][] = t("!sender-name (!sender-url) has sent you a message via your contact form at !site-name.", $variables, $options);
-      $message['body'][] = t("If you don't want to receive such emails, you can change your settings at !recipient-edit-url.", $variables, $options);
+      $message['subject'] .= t('[@site-name] @subject', $variables, $options);
+      $message['body'][] = t('Hello @recipient-name,', $variables, $options);
+      $message['body'][] = t("@sender-name (@sender-url) has sent you a message via your contact form at @site-name.", $variables, $options);
+      $message['body'][] = t("If you don't want to receive such emails, you can change your settings at @recipient-edit-url.", $variables, $options);
       $build = entity_view($contact_message, 'mail', $language->getId());
       $message['body'][] = (string) \Drupal::service('renderer')->renderPlain($build);
       break;
diff --git a/core/modules/contact/src/MailHandler.php b/core/modules/contact/src/MailHandler.php
index 308acf5..606292c 100644
--- a/core/modules/contact/src/MailHandler.php
+++ b/core/modules/contact/src/MailHandler.php
@@ -91,7 +91,7 @@ public function sendMailMessages(MessageInterface $message, AccountInterface $se
 
       // For the email message, clarify that the sender name is not verified; it
       // could potentially clash with a username on this site.
-      $sender_cloned->name = $this->t('!name (not verified)', array('!name' => $message->getSenderName()));
+      $sender_cloned->name = $this->t('@name (not verified)', array('@name' => $message->getSenderName()));
     }
 
     // Build email parameters.
diff --git a/core/modules/contact/src/Tests/ContactPersonalTest.php b/core/modules/contact/src/Tests/ContactPersonalTest.php
index 031ee75..c4f9509 100644
--- a/core/modules/contact/src/Tests/ContactPersonalTest.php
+++ b/core/modules/contact/src/Tests/ContactPersonalTest.php
@@ -79,12 +79,12 @@ function testSendPersonalContactMessage() {
     $this->assertEqual($mail['reply-to'], $this->webUser->getEmail());
     $this->assertEqual($mail['key'], 'user_mail');
     $variables = array(
-      '!site-name' => $this->config('system.site')->get('name'),
-      '!subject' => $message['subject[0][value]'],
-      '!recipient-name' => $this->contactUser->getUsername(),
+      '@site-name' => $this->config('system.site')->get('name'),
+      '@subject' => $message['subject[0][value]'],
+      '@recipient-name' => $this->contactUser->getUsername(),
     );
-    $this->assertEqual($mail['subject'], t('[!site-name] !subject', $variables), 'Subject is in sent message.');
-    $this->assertTrue(strpos($mail['body'], 'Hello ' . $variables['!recipient-name']) !== FALSE, 'Recipient name is in sent message.');
+    $this->assertEqual($mail['subject'], t('[@site-name] @subject', $variables), 'Subject is in sent message.');
+    $this->assertTrue(strpos($mail['body'], 'Hello ' . $variables['@recipient-name']) !== FALSE, 'Recipient name is in sent message.');
     $this->assertTrue(strpos($mail['body'], $this->webUser->getUsername()) !== FALSE, 'Sender name is in sent message.');
     $this->assertTrue(strpos($mail['body'], $message['message[0][value]']) !== FALSE, 'Message body is in sent message.');
 
diff --git a/core/modules/contact/src/Tests/ContactSitewideTest.php b/core/modules/contact/src/Tests/ContactSitewideTest.php
index 83f296f..651c283 100644
--- a/core/modules/contact/src/Tests/ContactSitewideTest.php
+++ b/core/modules/contact/src/Tests/ContactSitewideTest.php
@@ -129,7 +129,7 @@ function testSiteWideContact() {
     $max_length = EntityTypeInterface::BUNDLE_MAX_LENGTH;
     $max_length_exceeded = $max_length + 1;
     $this->addContactForm($id = Unicode::strtolower($this->randomMachineName($max_length_exceeded)), $label = $this->randomMachineName($max_length_exceeded), implode(',', array($recipients[0])), '', TRUE);
-    $this->assertText(format_string('Machine-readable name cannot be longer than !max characters but is currently !exceeded characters long.', array('!max' => $max_length, '!exceeded' => $max_length_exceeded)));
+    $this->assertText(format_string('Machine-readable name cannot be longer than @max characters but is currently @exceeded characters long.', array('@max' => $max_length, '@exceeded' => $max_length_exceeded)));
     $this->addContactForm($id = Unicode::strtolower($this->randomMachineName($max_length)), $label = $this->randomMachineName($max_length), implode(',', array($recipients[0])), '', TRUE);
     $this->assertRaw(t('Contact form %label has been added.', array('%label' => $label)));