diff --git a/lib/web/auth/mattermost/index.js b/lib/web/auth/mattermost/index.js
index 44922029..a0b440c7 100644
--- a/lib/web/auth/mattermost/index.js
+++ b/lib/web/auth/mattermost/index.js
@@ -8,11 +8,11 @@ const OAuthStrategy = require('passport-oauth2').Strategy
 const config = require('../../../config')
 const { setReturnToFromReferer, passportGeneralCallback } = require('../utils')
 
-let mattermostAuth = module.exports = Router()
+const mattermostAuth = module.exports = Router()
 
 const mattermostClient = new MattermostClient()
 
-let mattermostStrategy = new OAuthStrategy({
+const mattermostStrategy = new OAuthStrategy({
   authorizationURL: config.mattermost.baseURL + '/oauth/authorize',
   tokenURL: config.mattermost.baseURL + '/oauth/access_token',
   clientID: config.mattermost.clientID,