diff --git a/src/npc/surgery/surgery.js b/src/npc/surgery/surgery.js
index 44a2459bd0779c6d73e86eac2535f8611f19f8f9..4777bc268a2e2e0c4e56966a2663940ffbacd767 100644
--- a/src/npc/surgery/surgery.js
+++ b/src/npc/surgery/surgery.js
@@ -75,7 +75,7 @@ App.Medicine.Keys = {
  * @param {App.Entity.SlaveState} slave
  * @param {boolean} [cheat]
  */
-App.Medicine.Surgery.commit = function(surgery, slave, cheat) {
+App.Medicine.Surgery.commit = function(surgery, slave, cheat = false) {
 	V.surgeryType = surgery.surgeryType;
 	surgery.action(slave);
 	if (!cheat) {