diff --git a/resources/lang/sl_SI/intro.php b/resources/lang/sl_SI/intro.php
index e3c6739e9a..e945adcec8 100644
--- a/resources/lang/sl_SI/intro.php
+++ b/resources/lang/sl_SI/intro.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /**
  * intro.php
  * Copyright (c) 2017 thegrumpydictator@gmail.com