diff --git a/Command/YamlLintCommand.php b/Command/YamlLintCommand.php
index 3a432f275..94c93be98 100644
--- a/Command/YamlLintCommand.php
+++ b/Command/YamlLintCommand.php
@@ -46,7 +46,7 @@ public function __construct()
     /**
      * {@inheritdoc}
      */
-    protected function configure()
+    protected function configure(): void
     {
         parent::configure();