diff --git a/src/Codeception/Module/Symfony.php b/src/Codeception/Module/Symfony.php
index 7fcaa285..a5e5fb16 100644
--- a/src/Codeception/Module/Symfony.php
+++ b/src/Codeception/Module/Symfony.php
@@ -534,11 +534,11 @@ public function dontSeeEmailIsSent()
      * ?>
      * ```
      *
-     * @param $service
+     * @param string $service
      * @return mixed
      * @part services
      */
-    public function grabService($service)
+    public function grabService(string $service)
     {
         $container = $this->_getContainer();
         if (!$container->has($service)) {