diff --git a/erpnext/manufacturing/doctype/production_order/production_order.js b/erpnext/manufacturing/doctype/production_order/production_order.js
index 33acb41..c3e6f20 100644
--- a/erpnext/manufacturing/doctype/production_order/production_order.js
+++ b/erpnext/manufacturing/doctype/production_order/production_order.js
@@ -346,6 +346,7 @@
 			var max = flt(frm.doc.qty) - flt(frm.doc.produced_qty);
 		}
 
+		max = flt(max, precision("qty"));
 		frappe.prompt({fieldtype:"Float", label: __("Qty for {0}", [purpose]), fieldname:"qty",
 			description: __("Max: {0}", [max]), 'default': max },
 			function(data) {