Use 6to5 instead, it does the job and is fantastic.
> node6 es6app.js
> node6 -e "{let test = function *() {yield 3; yield 4}; let t = test(); console.log(t.next().value, t.next().value);}"
3 4
// mymodule.js
let test = function *() {yield 3; yield 4};
module.exports = test()
// index.js
require('node6')(__dirname) // enable node6 for this module (but not inner node_modules)
var t = require('./mymodule')
console.log(t.next().value) // 3
console.log(t.next().value) // 4