killbill-memoizeit

diff --git a/api/src/main/java/com/ning/billing/catalog/api/ProductCategory.java b/api/src/main/java/com/ning/billing/catalog/api/ProductCategory.java
index dca1f8d..22eb658 100644
--- a/api/src/main/java/com/ning/billing/catalog/api/ProductCategory.java
+++ b/api/src/main/java/com/ning/billing/catalog/api/ProductCategory.java
@@ -18,5 +18,6 @@ package com.ning.billing.catalog.api;
 
 public enum ProductCategory {
 	BASE,
-	ADD_ON
+	ADD_ON,
+	STANDALONE
 }