reverted:
--- b/comment_approver.info.yml
+++ a/comment_approver.info.yml
@@ -1,7 +1,8 @@
 name: Comment approver
 type: module
 description: A module to allow adminstrators to automatically approve comments
+core: 8.x
+core_version_requirement: ^8 || ^9
-core_version_requirement: ^9.3 || ^10
 package: Comment approver
 configure: comment_approver.comment_approver_settings
 
reverted:
--- b/comment_approver.module
+++ a/comment_approver.module
@@ -18,7 +18,7 @@
   switch ($route_name) {
     // Main module help for the comment_approver module.
     case 'help.page.comment_approver':
+      $output = '<pre>' . file_get_contents(drupal_get_path('module', 'comment_approver') . '/README.md') . '</pre>';
-      $output = '<pre>' . file_get_contents(\Drupal::service('extension.list.module')->getPath('comment_approver') . '/README.md') . '</pre>';
       return $output;
 
     default:
reverted:
--- b/src/Event/CommentApproverEvent.php
+++ a/src/Event/CommentApproverEvent.php
@@ -2,8 +2,8 @@
 
 namespace Drupal\comment_approver\Event;
 
-use Symfony\Contracts\EventDispatcher\Event;
 use Drupal\comment\CommentInterface;
+use Symfony\Component\EventDispatcher\Event;
 
 /**
  * Event that is fired when comment approver approves / blocks a comment.
diff -u b/tests/src/Functional/LoadTest.php b/tests/src/Functional/LoadTest.php
--- b/tests/src/Functional/LoadTest.php
+++ b/tests/src/Functional/LoadTest.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['comment_approver'];
+  protected static $modules = ['comment_approver'];
 
   /**
    * A user with permission to administer site configuration.
@@ -29,7 +29,7 @@
   /**
    * {@inheritdoc}
    */
-  protected function setUp(): void {
+  protected function setUp() {
     parent::setUp();
     $this->user = $this->drupalCreateUser(['administer site configuration']);
     $this->drupalLogin($this->user);