diff --git a/src/Form/VCardSettingsForm.php b/src/Form/VCardSettingsForm.php
index 783f29c..28a117e 100644
--- a/src/Form/VCardSettingsForm.php
+++ b/src/Form/VCardSettingsForm.php
@@ -31,7 +31,7 @@ class VCardSettingsForm extends ConfigFormBase {
   public function buildForm(array $form, FormStateInterface $form_state) {
     $config = $this->config('vcard.settings');
     if (!_vcard_init()) {
-      drupal_set_message($this->t('The PEAR package Contact_Vcard_Build (required by vcard.module) has not been installed properly, please read INSTALL.txt.'), 'warning');
+      $this->messenger()->addWarning($this->t('The PEAR package Contact_Vcard_Build (required by vcard.module) has not been installed properly, please read INSTALL.txt.'));
     }
 
     $form['display'] = [
@@ -94,7 +94,7 @@ class VCardSettingsForm extends ConfigFormBase {
     $display_settings_hcard = $form_state->getValue('vcard_display_profile_hcard');
     $config->set('vcard_display_profile_hcard', $display_settings_hcard)->save();
 
-    drupal_set_message($this->t('Configurations have been saved.'));
+    $this->messenger()->addStatus($this->t('Configurations have been saved.'));
   }
 
 }
diff --git a/vcard.info.yml b/vcard.info.yml
index 334ef8f..474ab7c 100755
--- a/vcard.info.yml
+++ b/vcard.info.yml
@@ -2,4 +2,5 @@ name: vCard
 type: module
 description: 'Allows vcard export of user data.'
 core: 8.x
+core_version_requirement: ^8 || ^9
 configure: vcard.settings
diff --git a/vcard.module b/vcard.module
index caa8cd4..baee594 100644
--- a/vcard.module
+++ b/vcard.module
@@ -253,21 +253,21 @@ function vcard_get($user) {
     $vcard->addParam('ENCODING', '8BIT');
   }
   else {
-    $vcard->setName(HTML::escape($name), '', '', '', '');
+    $vcard->setName(Html::escape($name), '', '', '', '');
     $vcard->addParam('ENCODING', '8BIT');
-    $vcard->setFormattedname(HTML::escape($name));
+    $vcard->setFormattedname(Html::escape($name));
     $vcard->addParam('ENCODING', '8BIT');
   }
 
   // Email.
   if (!empty($user->get('mail'))) {
     $mail = $user->get('mail')->value;
-    $vcard->addEmail(HTML::escape($mail));
+    $vcard->addEmail(Html::escape($mail));
     $vcard->addParam('ENCODING', '8BIT');
   }
 
   // Nickname.
-  $vcard->addNickname(HTML::escape($name));
+  $vcard->addNickname(Html::escape($name));
   $vcard->addParam('ENCODING', '8BIT');
 
   // Birthday.