diff --git a/autojs/src/main/assets/modules/__automator__.js b/autojs/src/main/assets/modules/__automator__.js
index bf4811c2..b6d45bbd 100644
--- a/autojs/src/main/assets/modules/__automator__.js
+++ b/autojs/src/main/assets/modules/__automator__.js
@@ -125,7 +125,7 @@ module.exports = function(runtime, global){
     }
 
     auto.setMode = function(modeStr){
-        if(typeof(mode) !== "string"){
+        if(typeof(modeStr) !== "string"){
             throw new TypeError("mode should be a string");
         }
         let mode = modes[modeStr];