diff --git a/Haas_Lathes_BIDC/Bechtel ST-20Y.cps b/Haas_Lathes_BIDC/Bechtel ST-20Y.cps
index e42b214..d351a50 100644
--- a/Haas_Lathes_BIDC/Bechtel ST-20Y.cps	
+++ b/Haas_Lathes_BIDC/Bechtel ST-20Y.cps	
@@ -1200,7 +1200,7 @@ function getToolHolderBIDCST20(toolNum) {
     case 12:
        return KM40A;
     default:
-      throw "INVALID ST20Y TOOL NUMBER: " + tool.number;
+      throw "INVALID ST20Y TOOL NUMBER: " + toolNum;
   }
 }