diff --git a/lib/compiler/passes/generate-js.js b/lib/compiler/passes/generate-js.js
index c35d8c4..4cc64a3 100644
--- a/lib/compiler/passes/generate-js.js
+++ b/lib/compiler/passes/generate-js.js
@@ -428,7 +428,7 @@ function generateJS(ast, options) {
         } else {
           let values = Array(n);
 
-          for (var i = 0; i < n; i++) {
+          for (let i = 0; i < n; i++) {
             values[i] = s(this.sp - n + 1 + i);
           }