diff --git a/compiler/Compiler.php b/compiler/Compiler.php
index 7fee467..feb4deb 100644
--- a/compiler/Compiler.php
+++ b/compiler/Compiler.php
@@ -133,6 +133,7 @@ class Compiler
         $codeStr = \implode("\n", $code);
 
         return <<<PHP
+declare(strict_types=1);
 namespace InnStudio\\Prober\\Components\\PreDefine;
 {$codeStr}
 PHP;