diff --git a/lib/web/auth/dropbox/index.ts b/lib/web/auth/dropbox/index.ts
index bf42b47a9..30dff424d 100644
--- a/lib/web/auth/dropbox/index.ts
+++ b/lib/web/auth/dropbox/index.ts
@@ -3,24 +3,29 @@ import { config } from '../../../config'
 import { passportGeneralCallback } from '../utils'
 import { Router, Response, NextFunction, Request } from 'express'
 import * as DropboxStrategy from 'passport-dropbox-oauth2'
+import { AuthMiddleware } from '../interface'
 
 export const dropboxAuth = Router()
 
-passport.use(new DropboxStrategy({
-  apiVersion: '2',
-  clientID: config.dropbox.clientID,
-  clientSecret: config.dropbox.clientSecret,
-  callbackURL: config.serverURL + '/auth/dropbox/callback'
-}, passportGeneralCallback))
+export const EmailMiddleware: AuthMiddleware = {
+  getMiddleware (): Router {
+    passport.use(new DropboxStrategy({
+      apiVersion: '2',
+      clientID: config.dropbox.clientID,
+      clientSecret: config.dropbox.clientSecret,
+      callbackURL: config.serverURL + '/auth/dropbox/callback'
+    }, passportGeneralCallback))
 
-dropboxAuth.get('/auth/dropbox', function (req: Request, res: Response, next: NextFunction) {
-  passport.authenticate('dropbox-oauth2')(req, res, next)
-})
+    dropboxAuth.get('/auth/dropbox', function (req: Request, res: Response, next: NextFunction) {
+      passport.authenticate('dropbox-oauth2')(req, res, next)
+    })
+    dropboxAuth.get('/auth/dropbox/callback',
+      passport.authenticate('dropbox-oauth2', {
+        successReturnToOrRedirect: config.serverURL + '/',
+        failureRedirect: config.serverURL + '/'
+      })
+    )
+    return dropboxAuth
+  }
 
-// dropbox auth callback
-dropboxAuth.get('/auth/dropbox/callback',
-  passport.authenticate('dropbox-oauth2', {
-    successReturnToOrRedirect: config.serverURL + '/',
-    failureRedirect: config.serverURL + '/'
-  })
-)
+}