diff --git a/paypal-checkout.js b/paypal-checkout.js
index 1a37af2..d28d858 100644
--- a/paypal-checkout.js
+++ b/paypal-checkout.js
@@ -24,7 +24,7 @@ PayPal.init = function (client_id, client_secret, env, opts) {
   if ("live" === env) {
     PayPal.__baseUrl = PayPal.__liveApiBaseUrl;
   } else {
-    PayPal.__baseUrl = PayPal.__sandboxUrl;
+    PayPal.__baseUrl = PayPal.__sandboxApiBaseUrl;
     console.debug("[PayPal Checkout] ENVIRONMENT=sandbox");
   }
   PayPal.__id = client_id;