diff --git a/src/app.ts b/src/app.ts
index 5de7001f..30ed5790 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -1,11 +1,11 @@
 import type http from 'http'
 import { withoutTrailingSlash } from 'ufo'
 import { defineLazyHandler } from './handler'
-import { toEventHandler, createEvent, isEventHandler } from './event'
+import { toEventHandler, createEvent, isEventHandler, defineEventHandler } from './event'
 import { createError, sendError } from './error'
 import { send, sendStream, isStream, MIMES } from './utils'
-import type { Handler, LazyHandler, Middleware, PromisifiedHandler } from './types'
-import type { EventHandler, CompatibilityEvent } from './event'
+import type { Handler, LazyHandler, Middleware } from './types'
+import type { EventHandler, CompatibilityEvent, CompatibilityEventHandler } from './event'
 
 export interface Layer {
   route: string
@@ -30,19 +30,17 @@ export type InputStack = InputLayer[]
 
 export type Matcher = (url: string, event?: CompatibilityEvent) => boolean
 
-export type RequestHandler = EventHandler | Handler | Middleware
-
 export interface AppUse {
-  (route: string | string [], handler: RequestHandler | RequestHandler[], options?: Partial<InputLayer>): App
-  (handler: RequestHandler | Handler[], options?: Partial<InputLayer>): App
+  (route: string | string [], handler: CompatibilityEventHandler | CompatibilityEventHandler[], options?: Partial<InputLayer>): App
+  (handler: CompatibilityEventHandler | CompatibilityEventHandler[], options?: Partial<InputLayer>): App
   (options: InputLayer): App
 }
 
-export type ApPromisifiedHandlerr = (req: http.IncomingMessage, res: http.ServerResponse) => Promise<any>
+export type NodeHandler = (req: http.IncomingMessage, res: http.ServerResponse) => void | Promise<void>
 
-export interface App extends ApPromisifiedHandlerr {
+export interface App extends NodeHandler {
   stack: Stack
-  _handler: PromisifiedHandler
+  handler: EventHandler
   use: AppUse
 }
 
@@ -54,20 +52,23 @@ export interface AppOptions {
 export function createApp (options: AppOptions = {}): App {
   const stack: Stack = []
 
-  const _handler = createHandler(stack, options)
+  const handler = createAppEventHandler(stack, options)
 
-  const app: App = function (req, res) {
+  const nodeHandler: NodeHandler = async function (req, res) {
     const event = createEvent(req, res)
-    return _handler(event).catch((error: Error) => {
+    try {
+      await handler(event)
+    } catch (err) {
       if (options.onError) {
-        return options.onError(error, event)
+        await options.onError(err as Error, event)
       }
-      return sendError(event, error, !!options.debug)
-    })
-  } as App
+      await sendError(event, err as Error, !!options.debug)
+    }
+  }
 
+  const app = nodeHandler as App
   app.stack = stack
-  app._handler = _handler
+  app.handler = handler
 
   // @ts-ignore
   app.use = (arg1, arg2, arg3) => use(app as App, arg1, arg2, arg3)
@@ -95,11 +96,10 @@ export function use (
   return app
 }
 
-export function createHandler (stack: Stack, options: AppOptions) {
+export function createAppEventHandler (stack: Stack, options: AppOptions) {
   const spacing = options.debug ? 2 : undefined
-  return async function handle (event: CompatibilityEvent) {
+  return defineEventHandler(async (event) => {
     event.req.originalUrl = event.req.originalUrl || event.req.url || '/'
-
     const reqUrl = event.req.url || '/'
     for (const layer of stack) {
       if (layer.route.length > 1) {
@@ -135,11 +135,16 @@ export function createHandler (stack: Stack, options: AppOptions) {
     if (!event.res.writableEnded) {
       throw createError({ statusCode: 404, statusMessage: 'Not Found' })
     }
-  }
+  })
 }
 
 function normalizeLayer (input: InputLayer) {
   let handler = input.handler
+  // @ts-ignore
+  if (handler.handler) {
+    // @ts-ignore
+    handler = handler.handler
+  }
   if (!isEventHandler(handler)) {
     if (input.lazy) {
       handler = defineLazyHandler(handler as LazyHandler)
diff --git a/src/event.ts b/src/event.ts
index 8b2d5aa9..1201ac24 100644
--- a/src/event.ts
+++ b/src/event.ts
@@ -54,7 +54,9 @@ export function isEventHandler (input: any): input is EventHandler {
   return '__is_handler__' in input
 }
 
-export function toEventHandler (handler: EventHandler | Handler | Middleware): EventHandler {
+export type CompatibilityEventHandler = EventHandler | Handler | Middleware
+
+export function toEventHandler (handler: CompatibilityEventHandler): EventHandler {
   if (isEventHandler(handler)) {
     return handler
   }
diff --git a/src/router.ts b/src/router.ts
index 437f9956..34b83726 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -2,17 +2,17 @@ import { createRouter as _createRouter } from 'radix3'
 import type { HTTPMethod } from './types'
 import { createError } from './error'
 import { defineEventHandler, EventHandler, toEventHandler } from './event'
-import type { RequestHandler } from './app'
+import type { CompatibilityEventHandler } from './event'
 
 export type RouterMethod = Lowercase<HTTPMethod>
 const RouterMethods: Lowercase<RouterMethod>[] = ['connect', 'delete', 'get', 'head', 'options', 'post', 'put', 'trace']
 
-export type AddWithMethod = (path: string, handler: RequestHandler) => Router
+export type AddWithMethod = (path: string, handler: CompatibilityEventHandler) => Router
 export type AddRouteShortcuts = Record<Lowercase<HTTPMethod>, AddWithMethod>
 
 export interface Router extends AddRouteShortcuts {
-  add: (path: string, handler: RequestHandler, method?: RouterMethod | 'all') => Router
-  handler: RequestHandler
+  add: (path: string, handler: CompatibilityEventHandler, method?: RouterMethod | 'all') => Router
+  handler: EventHandler
 }
 
 interface RouteNode {
diff --git a/src/utils/response.ts b/src/utils/response.ts
index eb42baac..abb94401 100644
--- a/src/utils/response.ts
+++ b/src/utils/response.ts
@@ -47,7 +47,7 @@ export function isStream (data: any) {
   return data && typeof data === 'object' && typeof data.pipe === 'function' && typeof data.on === 'function'
 }
 
-export function sendStream (event: CompatibilityEvent, data: any) {
+export function sendStream (event: CompatibilityEvent, data: any): Promise<void> {
   return new Promise((resolve, reject) => {
     data.pipe(event.res)
     data.on('end', () => resolve(undefined))