diff --git a/fasp.info.yml b/fasp.info.yml
index 30c6d54..ec4a604 100644
--- a/fasp.info.yml
+++ b/fasp.info.yml
@@ -1,5 +1,6 @@
 name: Forms AntiSpam
 description: Antispam module.
 core: 8.x
+core_version_requirement: ^8 || ^9
 type: module
 configure: fasp.settings.forms
diff --git a/src/FaspStyleGenerator.php b/src/FaspStyleGenerator.php
index 150864e..e42d7d2 100644
--- a/src/FaspStyleGenerator.php
+++ b/src/FaspStyleGenerator.php
@@ -1,6 +1,7 @@
 <?php
 
 namespace Drupal\fasp;
+use Drupal\Core\File\FileSystemInterface;
 
 /**
  * Class GenerateStyles.
@@ -46,8 +47,8 @@ class FaspStyleGenerator {
   private function createFile($content = '') {
     $file = FALSE;
     $dir = 'public://fasp';
-    if (file_prepare_directory($dir, FILE_CREATE_DIRECTORY)) {
-      $file = file_save_data($content, $dir . '/style.css', FILE_EXISTS_REPLACE);
+    if ($this->fileSystem->prepareDirectory($dir, FileSystemInterface::CREATE_DIRECTORY)) {
+      $file = file_save_data($content, $dir . '/style.css', FileSystemInterface::EXISTS_REPLACE);
       $file_usage = \Drupal::service('file.usage');
       $file_usage->add($file, 'fasp', 'style', 'fasp');
       $file->save();