diff --git a/lib/cash-in/cash-in-low.js b/lib/cash-in/cash-in-low.js
index 5b8066a0..d8329c50 100644
--- a/lib/cash-in/cash-in-low.js
+++ b/lib/cash-in/cash-in-low.js
@@ -102,8 +102,8 @@ function diff (oldTx, newTx) {
 }
 
 function ensureRatchet (oldField, newField, fieldKey) {
-  const monotonic = ['cryptoAtoms', 'fiat', 'send', 'sendConfirmed', 'operatorCompleted', 'timedout', 'txVersion', 'batched']
-  const free = ['sendPending', 'error', 'errorCode', 'customerId']
+  const monotonic = ['cryptoAtoms', 'fiat', 'send', 'sendConfirmed', 'operatorCompleted', 'timedout', 'txVersion', 'batched', 'discount']
+  const free = ['sendPending', 'error', 'errorCode', 'customerId', 'discountSource']
 
   if (_.isNil(oldField)) return true
   if (_.includes(fieldKey, monotonic)) return isMonotonic(oldField, newField, fieldKey)