diff --git a/src/npc/surgery/organFarm.js b/src/npc/surgery/organFarm.js
index 1e72b72e7a88029f86a7aa98d5dd87015a1f435b..3a0b8120e0c37432460eb86fdd9b67d1526b14f7 100644
--- a/src/npc/surgery/organFarm.js
+++ b/src/npc/surgery/organFarm.js
@@ -174,5 +174,10 @@ App.Medicine.OrganFarm.getSortedOrgans = function(slave) {
 			}
 		});
 	});
-	return App.Utils.topologicalSort(organs, dependencies);
+	try {
+		return App.Utils.topologicalSort(organs, dependencies);
+	} catch (e) { // closed loop
+		console.log(e.message);
+		return [];
+	}
 };