diff --git a/lib/models/subscription.dart b/lib/models/subscription.dart
index 1878b3f48..f2dcb76e0 100644
--- a/lib/models/subscription.dart
+++ b/lib/models/subscription.dart
@@ -1,5 +1,7 @@
 import 'dart:convert';
 
+const kFreeProductID = "free";
+
 class Subscription {
   final int id;
   final String productID;