diff --git a/src/JsPhpize/Nodes/Dyiade.php b/src/JsPhpize/Nodes/Dyiade.php
index ac0f322..168eb61 100644
--- a/src/JsPhpize/Nodes/Dyiade.php
+++ b/src/JsPhpize/Nodes/Dyiade.php
@@ -26,7 +26,7 @@ class Dyiade extends Value
      */
     protected $operator;
 
-    public function __construct($operator, Value $leftHand, Value $rightHand, array $before = null, array $after = null)
+    public function __construct($operator, Value $leftHand, Value $rightHand, ?array $before = null, ?array $after = null)
     {
         $this->operator = $operator;
         $this->leftHand = $leftHand;