diff --git a/src/js/app.js b/src/js/app.js
index 517cebe..d3881da 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -420,15 +420,14 @@ module.exports = new Vue({
             };
             delete settings.tool["tool-type"];
 
+            this.config["selected-tool-settings"][selected_tool] = settings;
             if (selected_tool == "pwncnc-vfd" && saveModbus) {
-                settings["modbus-spindle"]["regs"][5] = {
+                this.config["selected-tool-settings"][selected_tool]["modbus-spindle"]["regs"][5] = {
                   "reg-value": 6,
                   "reg-type": "stop-write",
                   "reg-addr": 40960,
                 };
             }
-
-            this.config["selected-tool-settings"][selected_tool] = settings;
             this.display_units = this.config.settings["units"];
   
             try {