diff --git a/appstore/notification.go b/appstore/notification.go
index 111e680..78f18c1 100644
--- a/appstore/notification.go
+++ b/appstore/notification.go
@@ -88,8 +88,7 @@ type SubscriptionNotification struct {
 	// HACK (msyrus): Separate Subscriptiton Notification from Notification verification response
 	Status                int                 `json:"status"`
 	Receipt               NotificationReceipt `json:"recipt"`
-	SubscriptionRetryFlag string              `json:"is_in_billing_retry_period"`
-
+	SubscriptionRetryFlag string              `json:"is_in_billing_retry_period,omitempty"`
 	// Posted if the notification_type is RENEWAL or INTERACTIVE_RENEWAL, and only if the renewal is successful.
 	// Posted also if the notification_type is INITIAL_BUY.
 	// Not posted for notification_type CANCEL.