diff --git a/src/Extend.php b/src/Extend.php
index 65717dc..bb67816 100644
--- a/src/Extend.php
+++ b/src/Extend.php
@@ -14,7 +14,7 @@ class Extend
 
     private $sandbox = false;
 
-    private $storeId;
+    protected $storeId;
 
     private $version;