diff --git a/pkg/cart/cart-grain.go b/pkg/cart/cart-grain.go
index 7633af3..7456e00 100644
--- a/pkg/cart/cart-grain.go
+++ b/pkg/cart/cart-grain.go
@@ -108,7 +108,7 @@ type CartGrain struct {
 	lastAccess             time.Time
 	lastChange             time.Time // unix seconds of last successful mutation (replay sets from event ts)
 	userId                 string
-	Version                uint
+	Version                uint                            `json:"version"`
 	InventoryReserved      bool                            `json:"inventoryReserved"`
 	Id                     CartId                          `json:"id"`
 	Items                  []*CartItem                     `json:"items"`