diff --git a/recaptcha.module b/recaptcha.module
index fe37e25f09a40c4901db43c666e00850edacf13b..5bb74d107203eb160bfe7656210c14deab3ac296 100644
--- a/recaptcha.module
+++ b/recaptcha.module
@@ -172,7 +172,7 @@ function recaptcha_captcha_validation($solution, $response, $element, $form_stat
   // Ensures the hostname matches. Required if "Domain Name Validation" is
   // disabled for credentials.
   if ($config->get('verify_hostname')) {
-    $recaptcha->setExpectedHostname($_SERVER['SERVER_NAME']);
+    $recaptcha->setExpectedHostname(\Drupal::request()->getHost());
   }
 
   $resp = $recaptcha->verify(