diff --git a/packages/nuxt3/src/builder/app.ts b/packages/nuxt3/src/builder/app.ts
index afcac3c9fe..cc04222743 100644
--- a/packages/nuxt3/src/builder/app.ts
+++ b/packages/nuxt3/src/builder/app.ts
@@ -4,7 +4,7 @@ import { Builder } from './builder'
 import { NuxtRoute, resolvePagesRoutes } from './pages'
 import { NuxtPlugin, resolvePlugins } from './plugins'
 export interface NuxtApp {
-  main: string
+  main?: string
   routes: NuxtRoute[]
   dir: string
   extensions: string[]
diff --git a/packages/nuxt3/src/builder/webpack/configs/client.ts b/packages/nuxt3/src/builder/webpack/configs/client.ts
index 8cd110b5d3..db1ffde384 100644
--- a/packages/nuxt3/src/builder/webpack/configs/client.ts
+++ b/packages/nuxt3/src/builder/webpack/configs/client.ts
@@ -2,6 +2,8 @@ import path from 'path'
 import querystring from 'querystring'
 import webpack from 'webpack'
 import { BundleAnalyzerPlugin } from 'webpack-bundle-analyzer'
+import type { ClientOptions } from 'webpack-hot-middleware'
+
 import { applyPresets, WebpackConfigContext } from '../utils/config'
 import { nuxt } from '../presets/nuxt'
 
@@ -47,14 +49,14 @@ function clientHMR (ctx: WebpackConfigContext) {
     return
   }
 
-  const clientOptions = options.build.hotMiddleware?.client || {}
+  const clientOptions = options.build.hotMiddleware?.client || {} as ClientOptions
   const hotMiddlewareClientOptions = {
     reload: true,
     timeout: 30000,
-    ansiColors: JSON.stringify(clientOptions.ansiColors || {}),
-    overlayStyles: JSON.stringify(clientOptions.overlayStyles || {}),
     path: `${options.router.base}/__webpack_hmr/${ctx.name}`.replace(/\/\//g, '/'),
     ...clientOptions,
+    ansiColors: JSON.stringify(clientOptions.ansiColors || {}),
+    overlayStyles: JSON.stringify(clientOptions.overlayStyles || {}),
     name: ctx.name
   }
   const hotMiddlewareClientOptionsStr = querystring.stringify(hotMiddlewareClientOptions)
diff --git a/packages/nuxt3/src/builder/webpack/plugins/externals.ts b/packages/nuxt3/src/builder/webpack/plugins/externals.ts
index e1b951fc81..704917c39e 100644
--- a/packages/nuxt3/src/builder/webpack/plugins/externals.ts
+++ b/packages/nuxt3/src/builder/webpack/plugins/externals.ts
@@ -31,7 +31,7 @@ function readDir (dirName) {
         }
         return module
       })
-      .reduce(function (prev, next) {
+      .reduce<string[]>(function (prev, next) {
         return prev.concat(next)
       }, [])
   } catch (e) {
diff --git a/packages/nuxt3/src/builder/webpack/plugins/warning-ignore.ts b/packages/nuxt3/src/builder/webpack/plugins/warning-ignore.ts
index b61901778c..d111997a78 100644
--- a/packages/nuxt3/src/builder/webpack/plugins/warning-ignore.ts
+++ b/packages/nuxt3/src/builder/webpack/plugins/warning-ignore.ts
@@ -1,4 +1,7 @@
+import { WebpackError } from 'webpack'
 export default class WarningIgnorePlugin {
+  filter: (warn: WebpackError) => boolean
+
   constructor (filter) {
     this.filter = filter
   }
diff --git a/packages/nuxt3/src/builder/webpack/utils/index.ts b/packages/nuxt3/src/builder/webpack/utils/index.ts
index 2daa4f2283..338d7a6a30 100644
--- a/packages/nuxt3/src/builder/webpack/utils/index.ts
+++ b/packages/nuxt3/src/builder/webpack/utils/index.ts
@@ -1,2 +1 @@
-export { default as StyleLoader } from './style-loader'
 export { reservedVueTags } from './reserved-tags'
diff --git a/packages/nuxt3/src/builder/webpack/utils/mfs.ts b/packages/nuxt3/src/builder/webpack/utils/mfs.ts
index 03eb031ae9..2f55362e6d 100644
--- a/packages/nuxt3/src/builder/webpack/utils/mfs.ts
+++ b/packages/nuxt3/src/builder/webpack/utils/mfs.ts
@@ -2,12 +2,14 @@ import path from 'path'
 import pify from 'pify'
 import { Volume, createFsFromVolume } from 'memfs'
 
+import type { IFs } from 'memfs'
+
 export function createMFS () {
   // Create a new volume
   const fs = createFsFromVolume(new Volume())
 
   // Clone to extend
-  const _fs = { ...fs }
+  const _fs : Partial<IFs> & { join?(...paths: string[]): string } = { ...fs }
 
   // fs.join method is (still) expected by webpack-dev-middleware
   // There might be differences with https://github.com/webpack/memory-fs/blob/master/lib/join.js
diff --git a/packages/nuxt3/src/config/config/_common.ts b/packages/nuxt3/src/config/config/_common.ts
index 28cd98c699..caac58a06f 100644
--- a/packages/nuxt3/src/config/config/_common.ts
+++ b/packages/nuxt3/src/config/config/_common.ts
@@ -81,6 +81,7 @@ export type NuxtModule = string | ModuleHandler | [string | ModuleHandler, any]
 export type ServerMiddleware = string | { path: string, prefix?: boolean, handler: string | express.NextFunction } | express.NextFunction
 
 interface CommonConfiguration {
+  _majorVersion: Number
   _modules: NuxtModule[]
   _nuxtConfigFile?: string
   alias: Record<string, string>
@@ -129,6 +130,7 @@ interface CommonConfiguration {
 }
 
 export default (): CommonConfiguration => ({
+  _majorVersion: undefined,
   // Env
   dev: Boolean(env.dev),
   test: Boolean(env.test),
@@ -170,6 +172,7 @@ export default (): CommonConfiguration => ({
   _nuxtConfigFile: undefined,
   srcDir: undefined,
   buildDir: '.nuxt',
+  vite: false,
   modulesDir: [
     'node_modules'
   ],
diff --git a/packages/nuxt3/src/config/config/router.ts b/packages/nuxt3/src/config/config/router.ts
index 4b809a437c..f7228ae837 100644
--- a/packages/nuxt3/src/config/config/router.ts
+++ b/packages/nuxt3/src/config/config/router.ts
@@ -1,4 +1,4 @@
-import { RouteRecordRaw, ScrollBehavior } from 'vue-router'
+import { RouteRecordRaw, RouterScrollBehavior } from 'vue-router'
 
 type UnionToIntersection<T> = (T extends any ? (k: T) => void : never) extends ((k: infer U) => void) ? U : never
 type RouteConfig = UnionToIntersection<RouteRecordRaw>
@@ -25,7 +25,7 @@ export interface RouterConfigurationNormalized {
   prefetchPayloads: boolean
   routes: Route[]
   routeNameSplitter: string
-  scrollBehavior: null | ScrollBehavior
+  scrollBehavior: null | RouterScrollBehavior
   stringifyQuery: boolean
   trailingSlash?: boolean
 }