diff --git a/index.php b/index.php
index 3e53521..2506118 100644
--- a/index.php
+++ b/index.php
@@ -48,10 +48,20 @@ function logger(string $message): void
 new class {
     private const IMAGE_DIR = __DIR__ . '/images';
 
-    private ?string $imageFile = null;
-    private ?string $logFile = null;
-
-    private array $params;
+    /**
+     * @var string|null
+     */
+    private $imageFile;
+
+    /**
+     * @var string|null
+     */
+    private $logFile;
+
+    /**
+     * @var array
+     */
+    private $params;
 
     public function __construct()
     {