refactor: polyfill ??
diff --git a/erpnext/manufacturing/doctype/bom/bom.js b/erpnext/manufacturing/doctype/bom/bom.js
index dd437dd..7e755d4 100644
--- a/erpnext/manufacturing/doctype/bom/bom.js
+++ b/erpnext/manufacturing/doctype/bom/bom.js
@@ -686,7 +686,7 @@
 		(data) => {
 			const row = locals[cdt][cdn];
 			row.stock_qty = (frm.doc.quantity * data.percent) / 100;
-			row.qty = row.stock_qty / (row.conversion_factor ?? 1);
+			row.qty = row.stock_qty / (row.conversion_factor || 1);
 			refresh_field("scrap_items");
 		},
 		__("Set Process Loss Item Quantity"),