diff --git a/src/adapters/github/index.ts b/src/adapters/github/index.ts
index c421c02..7e63d6e 100644
--- a/src/adapters/github/index.ts
+++ b/src/adapters/github/index.ts
@@ -1,4 +1,5 @@
 import * as cacheManager from 'cache-manager'
+import * as jwt from 'jsonwebtoken'
 import {Context} from '../../context'
 import {GitHubAPI} from '../../github'
 import {logger} from '../../logger'
@@ -17,12 +18,24 @@ function isUnauthenticatedEvent (context) {
 
 export class GitHubAdapter {
   public log: LoggerWithTarget
-  public jwt: () => string
+  public id: number
+  public cert: string
 
-  constructor({jwt}) {
+  constructor({id, cert}) {
+    this.id = id
+    this.cert = cert
     this.log = wrapLogger(logger, logger)
-    this.jwt = jwt
+  }
 
+  public jwt() {
+    const payload = {
+      exp: Math.floor(Date.now() / 1000) + 60,  // JWT expiration time
+      iat: Math.floor(Date.now() / 1000),       // Issued at time
+      iss: this.id                           // GitHub App ID
+    }
+
+    // Sign with RSA SHA256
+    return jwt.sign(payload, this.cert, {algorithm: 'RS256'})
   }
 
   public async createContext (event) {
diff --git a/src/github-app.ts b/src/github-app.ts
deleted file mode 100644
index bada1a0..0000000
--- a/src/github-app.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-import * as jwt from 'jsonwebtoken'
-
-export const createApp = (options: AppOptions) => {
-  return () => {
-    const payload = {
-      exp: Math.floor(Date.now() / 1000) + 60,  // JWT expiration time
-      iat: Math.floor(Date.now() / 1000),       // Issued at time
-      iss: options.id                           // GitHub App ID
-    }
-
-    // Sign with RSA SHA256
-    return jwt.sign(payload, options.cert, {algorithm: 'RS256'})
-  }
-}
-
-export interface AppOptions {
-  id: number
-  cert: string
-}
diff --git a/src/github/logging.ts b/src/github/logging.ts
index 9248721..0248804 100644
--- a/src/github/logging.ts
+++ b/src/github/logging.ts
@@ -14,7 +14,7 @@ export function addLogging (client: GitHubAPI, logger: Logger) {
   })
   client.hook.after('request', (result, options) => {
     const {method, url, headers, ...params} = options
-    const msg = `GitHub request: ${method} ${url} - ${result.headers.status}`
+    const msg = `GitHub request: ${method} ${url} - ${result.meta.status}`
     logger.debug({params}, msg)
   })
 }
diff --git a/src/index.ts b/src/index.ts
index 1bbc3d0..5552104 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,7 +3,6 @@ import * as express from 'express'
 import {GitHubAdapter} from './adapters/github'
 import {Application, WebhookEvent} from './application'
 import {Context} from './context'
-import {createApp} from './github-app'
 import {logger} from './logger'
 import {resolve} from './resolver'
 import {createServer} from './server'
@@ -25,7 +24,6 @@ export class Probot {
 
   private options: Options
   private apps: Application[]
-  private app: () => string
   private adapter: GitHubAdapter
 
   constructor(options: Options) {
@@ -35,12 +33,11 @@ export class Probot {
     this.logger = logger
     this.apps = []
     this.webhook = new Webhooks({path: options.webhookPath, secret: options.secret})
-    this.app = createApp({ id: options.id, cert: options.cert })
     this.server = createServer({logger})
     this.server.use(this.webhook.middleware)
 
 
-    this.adapter = new GitHubAdapter({jwt: this.app})
+    this.adapter = new GitHubAdapter({ id: options.id, cert: options.cert })
 
     // Log all received webhooks
     this.webhook.on('*', (event: any) => {
diff --git a/test/plugins/helper.js b/test/plugins/helper.js
index 48d5895..a722ee1 100644
--- a/test/plugins/helper.js
+++ b/test/plugins/helper.js
@@ -5,7 +5,8 @@ const {GitHubAdapter} = require('../../src/adapters/github')
 
 module.exports = {
   createApp (plugin = () => {}) {
-    const adapter = new GitHubAdapter({jwt: jest.fn().mockReturnValue('test')})
+    const adapter = new GitHubAdapter({})
+    adapter.jwt = jest.fn().mockReturnValue('test')
     const app = new Application({adapter})
     plugin(app)
     return app