diff --git a/erpnext/public/js/controllers/transaction.js b/erpnext/public/js/controllers/transaction.js
index 4e76f28e0a0df2c1e94351c97a010c35ffae00e4..69f0014067431b3d70286df5bea619ec97ec2bd9 100644
--- a/erpnext/public/js/controllers/transaction.js
+++ b/erpnext/public/js/controllers/transaction.js
@@ -608,6 +608,7 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 		// Experimental: This will be removed once stability is achieved.
 		if (!frappe.boot.sysdefaults.use_legacy_js_reactivity) {
 			var item = frappe.get_doc(cdt, cdn);
+
 			frappe.call({
 				doc: doc,
 				method: "process_item_selection",
@@ -633,6 +634,7 @@ 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)) {