diff --git a/lib/Stripe/ApiResource.php b/lib/Stripe/ApiResource.php
index <HASH>..<HASH> 100644
--- a/lib/Stripe/ApiResource.php
+++ b/lib/Stripe/ApiResource.php
@@ -118,10 +118,10 @@ abstract class Stripe_ApiResource extends Stripe_Object
     return Stripe_Util::convertToStripeObject($response, $apiKey);
   }
 
-  protected function _scopedSave($class, $apiKey=null)
+  protected function _scopedSave($class)
   {
     self::_validateCall('save');
-    $requestor = new Stripe_ApiRequestor($apiKey);
+    $requestor = new Stripe_ApiRequestor($this->_apiKey);
     $params = $this->serializeParameters();
 
     if (count($params) > 0) {
diff --git a/lib/Stripe/Customer.php b/lib/Stripe/Customer.php
index <HASH>..<HASH> 100644
--- a/lib/Stripe/Customer.php
+++ b/lib/Stripe/Customer.php
@@ -44,7 +44,7 @@ class Stripe_Customer extends Stripe_ApiResource
   public function save()
   {
     $class = get_class();
-    return self::_scopedSave($class, $this->_apiKey);
+    return self::_scopedSave($class);
   }
 
   /**
Always try to pass a local API key when saving