diff --git a/src/ZipCodeValidator/Constraints/ZipCode.php b/src/ZipCodeValidator/Constraints/ZipCode.php
index 32af26a..258a418 100644
--- a/src/ZipCodeValidator/Constraints/ZipCode.php
+++ b/src/ZipCodeValidator/Constraints/ZipCode.php
@@ -20,7 +20,7 @@ class ZipCode extends Constraint
     public bool $strict = true;
     public bool $caseSensitiveCheck = true;
 
-    public function __construct(mixed $options = null, array $groups = [], mixed $payload = null)
+    public function __construct(mixed $options = null, ?array $groups = null, mixed $payload = null)
     {
         if (is_string($options)) {
             $options = array(