diff --git a/erpnext/public/js/controllers/transaction.js b/erpnext/public/js/controllers/transaction.js
index 66c54ec6639..7b63d78c09b 100644
--- a/erpnext/public/js/controllers/transaction.js
+++ b/erpnext/public/js/controllers/transaction.js
@@ -558,6 +558,7 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 
 		item.weight_per_unit = 0;
 		item.weight_uom = '';
+		item.uom = null // make UOM blank to update the existing UOM when item changes
 		item.conversion_factor = 0;
 
 		if(['Sales Invoice', 'Purchase Invoice'].includes(this.frm.doc.doctype)) {