diff --git a/externalauth_gitlab.info.yml b/externalauth_gitlab.info.yml
index 302a819..ed5fd34 100644
--- a/externalauth_gitlab.info.yml
+++ b/externalauth_gitlab.info.yml
@@ -2,6 +2,7 @@ name: Externalauth Gitlab OAuth2 Connector
 type: module
 description: 'Authenticate via oauth and a running gitlab instance'
 core: 8.x
+core_version_requirement: ^8 || ^9
 package: 'Custom'
 dependencies:
   - externalauth:externalauth
diff --git a/src/Controller/LoginController.php b/src/Controller/LoginController.php
index d52f8a8..a326841 100644
--- a/src/Controller/LoginController.php
+++ b/src/Controller/LoginController.php
@@ -114,17 +114,17 @@ class LoginController extends ControllerBase {
         // We got an access token, let's now get the user's details.
         $gitlab_user = $provider->getResourceOwner($token);
         $this->doLogin($gitlab_user, $token->getToken());
-        drupal_set_message($this->t('Successfully logged in via gitlab.'));
+        $this->messenger()->addStatus($this->t('Successfully logged in via gitlab.'));
         return new RedirectResponse(Url::fromRoute('<front>')->toString(), 302);
 
       }
       catch (\Exception $e) {
-        drupal_set_message($this->t(
+        $this->messenger()->addError($this->t(
           'Could not log in via gitlab, error: %error',
           [
             '%error' => $e->getMessage(),
           ]
-        ), 'error');
+        ));
         return new RedirectResponse(Url::fromRoute('<front>')->toString(), 302);
       }
     }