diff --git a/KerbalConstructionTime/KerbalConstructionTime-1-1.4.6.12.ckan b/KerbalConstructionTime/KerbalConstructionTime-1-1.4.6.12.ckan
index 797c77396e..768afd9d7b 100644
--- a/KerbalConstructionTime/KerbalConstructionTime-1-1.4.6.12.ckan
+++ b/KerbalConstructionTime/KerbalConstructionTime-1-1.4.6.12.ckan
@@ -44,6 +44,11 @@
             "name": "KerbalAlarmClock"
         }
     ],
+    "conflicts": [
+        {
+            "name": "KerbalConstructionTime-173"
+        }
+    ],
     "install": [
         {
             "file": "GameData/KerbalConstructionTime",