[1225] Nuxt is not a constructor error on latest version (1.0.0-rc3)

Hi, I am using the nuxt socket example and after upgrading my nuxt to recent version I keep receiving error on this line of code in server.js

let config = require('./nuxt.config.js') const nuxt = new Nuxt(config)

Stack trace:

C:\Users\kpandurangan\Desktop\NodeJS\nuxt-sample1\server.js:18 const nuxt = new Nuxt(config) ^ TypeError: Nuxt is not a constructor at Object.<anonymous> (C:\Users\kpandurangan\Desktop\NodeJS\nuxt-sample1\server.js:18:14) at Module._compile (module.js:570:32) at Object.Module._extensions..js (module.js:579:10) at Module.load (module.js:487:32) at tryModuleLoad (module.js:446:12) at Function.Module._load (module.js:438:3) at Module.runMain (module.js:604:10) at run (bootstrap_node.js:393:7) at startup (bootstrap_node.js:150:9) at bootstrap_node.js:508:3

The same code works fine on with NUXT version 0.10.7