[1419] File '/xxxx/xxxxx/node_modules/nuxt/index.d.ts' is not a module.

I try to move my project to ts, then this error raise

error TS2306: File '/xxxx/xxxxx/node_modules/nuxt/index.d.ts' is not a module.

here is tsconfig.json

{
  "compilerOptions": {
    "target": "es5",
    "lib": [
      "dom",
      "es5",
      "es2015"
    ],
    "module": "es2015",
    "moduleResolution": "node",
    "allowJs": true,
    "experimentalDecorators": true,
    //"declaration": true,
    "noImplicitAny": false,
    "noImplicitThis": false,
    "strictNullChecks": true,
    "removeComments": true,
    "suppressImplicitAnyIndexErrors": true,
    "allowSyntheticDefaultImports": true,
    "baseUrl": ".",
    "paths": {
      "~": ["./"],
      "~assets/*": ["./assets/*"],
      "~components/*": ["./components/*"],
      "~middleware/*": ["./middleware/*"],
      "~pages/*": ["./pages/*"],
      "~plugins/*": ["./plugins/*"],
      "~static/*": ["./static/*"]
    }
  }
}

here is server.ts , error on import { Nuxt, Builder } from 'nuxt'

import Koa from 'koa'
import { Nuxt, Builder } from 'nuxt'

import config from '../nuxt.config.js'

const app = new Koa()
const host = process.env.HOST || '127.0.0.1'
const port = parseInt(process.env.PORT || '3000')


config.dev = !(app.env === 'production')

// Instantiate nuxt.js
const nuxt = new Nuxt(config)

// Build in development
if (config.dev) {
  const builder = new Builder(nuxt)
  builder.build().catch(e => { 
    console.error(e); // eslint-disable-line no-console
    process.exit(1)
  })
}

app.use(ctx => {
  ctx.status = 200 // koa defaults to 404 when it sees that status is unset

  return new Promise((resolve, reject) => {
    ctx.res.on('close', resolve)
    ctx.res.on('finish', resolve)
    nuxt.render(ctx.req, ctx.res, promise => {
      // nuxt.render passes a rejected promise into callback on error.
      promise.then(resolve).catch(reject)
    })
  })
})

app.listen(port, host)
console.log('Server listening on ' + host + ':' + port) 

and check index.d.ts in node_modules/nuxt/ the content is

//These declarations allow TypeScript to import non-js/ts files without the file extensions (such as .vue files)

declare module "~components/*" {}
declare module "~layouts/*" {}
declare module "~pages/*" {}
declare module "~assets/*" {}
declare module "~static/*" {}

I remove index.d.ts and project can run

I check typescript 2.x doc, It seem that module can't use like this