diff --git a/src/DuplicateField.php b/src/DuplicateField.php
index e28049a..423dc21 100644
--- a/src/DuplicateField.php
+++ b/src/DuplicateField.php
@@ -14,7 +14,7 @@ class DuplicateField extends Field
      */
     public $component = 'duplicate-field';
 
-    public function __construct(string $name, ? string $attribute = null, ? mixed $resolveCallback = null)
+    public function __construct(string $name, string $attribute = null, $resolveCallback = null)
     {
         parent::__construct(null, null, null);