diff --git a/src/Controller/LocalTasksController.php b/src/Controller/LocalTasksController.php
index 46a1dbf..c05dcee 100644
--- a/src/Controller/LocalTasksController.php
+++ b/src/Controller/LocalTasksController.php
@@ -47,7 +47,7 @@ public static function create(ContainerInterface $container): LocalTasksControll
    * @return array<string, mixed>
    *   An array containing the form definition.
    */
-  public function dynamicTasks(string $type = NULL): array {
+  public function dynamicTasks(?string $type = NULL): array {
     if (empty($type)) {
       return $this->formBuilder->getForm('\Drupal\os2web_audit\Form\SettingsForm');
     }
diff --git a/src/Exception/AuditException.php b/src/Exception/AuditException.php
index 1ebd9ee..b5344d4 100644
--- a/src/Exception/AuditException.php
+++ b/src/Exception/AuditException.php
@@ -16,7 +16,7 @@ class AuditException extends \Exception {
    */
   private string $pluginName = 'Unknown plugin';
 
-  public function __construct(string $message = "", int $code = 0, \Throwable $previous = NULL, ?string $pluginName = NULL) {
+  public function __construct(string $message = "", int $code = 0, ?\Throwable $previous = NULL, ?string $pluginName = NULL) {
     parent::__construct($message, $code, $previous);
 
     if (isset($pluginName)) {