diff --git a/lib/build.js b/lib/build.js
index a5793131a3..a12807e06c 100644
--- a/lib/build.js
+++ b/lib/build.js
@@ -97,8 +97,21 @@ export function options () {
 }
 
 export async function build () {
-  // Initialize modules first
-  await this.module.init()
+  // Avoid calling this method multiple times
+  if (this._buildDone) {
+    return this
+  }
+  // If building
+  if (this._building) {
+    return new Promise((resolve) => {
+      setTimeout(() => {
+        resolve(this.build())
+      }, 300)
+    })
+  }
+  this._building = true
+  // Wait for Nuxt.js to be ready
+  await this.ready()
   // Check if pages dir exists and warn if not
   this._nuxtPages = typeof this.createRoutes !== 'function'
   if (this._nuxtPages) {
@@ -123,6 +136,8 @@ export async function build () {
   await generateRoutesAndFiles.call(this)
   // Generate .nuxt/dist/ files
   await buildFiles.call(this)
+  // Flag to set that building is done
+  this._buildDone = true
   return this
 }
 
diff --git a/lib/module.js b/lib/module.js
index 106f04b41c..f16669697a 100755
--- a/lib/module.js
+++ b/lib/module.js
@@ -13,18 +13,16 @@ class Module {
     this.nuxt = nuxt
     this.options = nuxt.options
     this.modules = []
-    this.initialized = false
+    this.initing = this.ready()
   }
 
-  async init () {
-    if (this.initialized) {
-      debug('[nuxt] Modules are already initialized')
+  async ready () {
+    if (this.initing) {
+      await this.initing
       return
     }
     // Install all modules in sequence
     await sequence(this.options.modules, this.addModule.bind(this))
-    // Indicate modules are already initialized
-    this.initialized = true
   }
 
   addVendor (vendor) {
diff --git a/lib/nuxt.js b/lib/nuxt.js
index c045e483c2..bce21038cc 100644
--- a/lib/nuxt.js
+++ b/lib/nuxt.js
@@ -16,7 +16,7 @@ import * as utils from './utils'
 class Nuxt {
   constructor (options = {}) {
     const defaults = {
-      dev: true,
+      dev: (process.env.NODE_ENV !== 'production'),
       buildDir: '.nuxt',
       env: {},
       head: {
@@ -72,6 +72,8 @@ class Nuxt {
     }
     if (typeof options.transition === 'string') options.transition = { name: options.transition }
     this.options = _.defaultsDeep(options, defaults)
+    // Ready variable
+    this._ready = false
     // Env variables
     this.dev = this.options.dev
     // Explicit srcDir, rootDir and buildDir
@@ -121,6 +123,21 @@ class Nuxt {
     this.utils = utils
     // Add module integration
     this.module = new Module(this)
+    // Init nuxt.js
+    this.ready()
+    // Launch build in development but don't wait for him to be finished
+    if (this.dev) {
+      this.build()
+    }
+    // Return nuxt.js instance
+    return this
+  }
+
+  async ready () {
+    if (this._ready) return this
+    // Init modules
+    await this.module.ready()
+    this._ready = true
   }
 
   close (callback) {
diff --git a/lib/render.js b/lib/render.js
index ccdaefc07f..ee8d371d9c 100644
--- a/lib/render.js
+++ b/lib/render.js
@@ -23,6 +23,9 @@ export async function render (req, res) {
       }, 1000)
     })
   }
+  // Wait for nuxt.js to be ready
+  await this.ready()
+  // Get context
   const context = getContext(req, res)
   res.statusCode = 200
   try {
@@ -92,6 +95,7 @@ export async function render (req, res) {
       return err
     }
     const html = this.errorTemplate({
+  /* istanbul ignore if */
       error: err,
       stack: ansiHTML(encodeHtml(err.stack))
     })
@@ -104,6 +108,9 @@ export async function render (req, res) {
 }
 
 export async function renderRoute (url, context = {}) {
+  // Wait for modules to be initialized
+  await this.ready()
+  // Log rendered url
   debug(`Rendering url ${url}`)
   // Add url and isSever to the context
   context.url = url
@@ -165,6 +172,7 @@ export async function renderAndGetWindow (url, opts = {}) {
   const { window } = await jsdom.JSDOM.fromURL(url, options)
   // If Nuxt could not be loaded (error from the server-side)
   const nuxtExists = window.document.body.innerHTML.includes('window.__NUXT__')
+  /* istanbul ignore if */
   if (!nuxtExists) {
     let error = new Error('Could not load the nuxt app')
     error.body = window.document.body.innerHTML
diff --git a/lib/server.js b/lib/server.js
index 5ad4439529..63766e4563 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -10,12 +10,15 @@ class Server {
     // Initialize
     this.app = connect()
     this.server = http.createServer(this.app)
-    // Add Middleware
-    this.nuxt.options.serverMiddleware.forEach(m => {
-      this.useMiddleware(m)
+    this.nuxt.ready()
+    .then(() => {
+      // Add Middleware
+      this.nuxt.options.serverMiddleware.forEach(m => {
+        this.useMiddleware(m)
+      })
+      // Add default render middleware
+      this.useMiddleware(this.render.bind(this))
     })
-    // Add default render middleware
-    this.useMiddleware(this.render.bind(this))
     return this
   }
 
@@ -45,8 +48,11 @@ class Server {
   listen (port, host) {
     host = host || '127.0.0.1'
     port = port || 3000
-    this.server.listen(port, host, () => {
-      console.log('Ready on http://%s:%s', host, port) // eslint-disable-line no-console
+    this.nuxt.ready()
+    .then(() => {
+      this.server.listen(port, host, () => {
+        console.log('Ready on http://%s:%s', host, port) // eslint-disable-line no-console
+      })
     })
     return this
   }
diff --git a/test/index.test.js b/test/index.test.js
index 53f05b9afa..f910f1ea5e 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -7,12 +7,14 @@ test('Nuxt.js Class', t => {
   t.is(typeof Nuxt, 'function')
 })
 
-test('Nuxt.js Instance', async t => {
+test.serial('Nuxt.js Instance', async t => {
+  process.env.NODE_ENV = 'production'
   const nuxt = new Nuxt()
   t.is(typeof nuxt, 'object')
-  t.is(nuxt.dev, true)
+  t.is(nuxt.dev, false)
   t.is(typeof nuxt.build, 'function')
   t.is(typeof nuxt.generate, 'function')
+  delete process.env.NODE_ENV
 })
 
 test.serial('Fail when build not done and try to render', async t => {