diff --git a/gulp/mod.js b/gulp/mod.js
index 338173b8..3575a801 100644
--- a/gulp/mod.js
+++ b/gulp/mod.js
@@ -1,3 +1,3 @@
 module.exports = function (source, map) {
-    return source + `\nexport const __$S__=(n,v)=>eval("function(v){" + n + "=v}")(v)`;
+    return source + `\nexport const __$S__=(n,v)=>eval("(function(v){" + n + "=v})")(v)`;
 };