diff --git a/erpnext/manufacturing/doctype/work_order/work_order.js b/erpnext/manufacturing/doctype/work_order/work_order.js
index 1789a1f..7bc2138 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.js
+++ b/erpnext/manufacturing/doctype/work_order/work_order.js
@@ -395,6 +395,11 @@
 				}
 			});
 		}
+	},
+
+	additional_operating_cost: function(frm) {
+		erpnext.work_order.calculate_cost(frm.doc);
+		erpnext.work_order.calculate_total_cost(frm);
 	}
 });
 
@@ -534,9 +539,8 @@
 	},
 
 	calculate_total_cost: function(frm) {
-		var variable_cost = frm.doc.actual_operating_cost ?
-			flt(frm.doc.actual_operating_cost) : flt(frm.doc.planned_operating_cost);
-		frm.set_value("total_operating_cost", (flt(frm.doc.additional_operating_cost) + variable_cost));
+		let variable_cost = flt(frm.doc.actual_operating_cost) || flt(frm.doc.planned_operating_cost);
+		frm.set_value("total_operating_cost", (flt(frm.doc.additional_operating_cost) + variable_cost))
 	},
 
 	set_default_warehouse: function(frm) {