diff --git a/src/helpers/mail.ts b/src/helpers/mail.ts
index 901c5f5..c8291d1 100644
--- a/src/helpers/mail.ts
+++ b/src/helpers/mail.ts
@@ -55,7 +55,7 @@ export default class Mail{
     });
   }
 
-  static send (mailAddress, subject, content, f = () => {}) {  // callback, executed empty or with error
+  static send (mailAddress, subject, content, f: (x?) => void = () => {}) {  // callback, executed empty or with error
     if (process.env.NODE_ENV === 'production') {  // only send mails in production
       axios({
         method: 'post',
diff --git a/src/routes/user.ts b/src/routes/user.ts
index 7b43449..c8ebdc2 100644
--- a/src/routes/user.ts
+++ b/src/routes/user.ts
@@ -5,7 +5,7 @@ import _ from 'lodash';
 
 import UserValidate from './validate/user';
 import UserModel from '../models/user';
-import mail from '../helpers/mail';
+import Mail from '../helpers/mail';
 import res400 from './validate/res400';
 import db from '../db';
 
@@ -133,7 +133,7 @@ router.post('/user/passreset', (req, res, next) => {
           if (err) return next(err);
 
           // send email
-          mail(data[0].email, 'Your new password for the DeFinMa database',
+          Mail.send(data[0].email, 'Your new password for the DeFinMa database',
             'Hi, <br><br> You requested to reset your password.<br>Your new password is:<br><br>' + newPass + '' +
             '<br><br>If you did not request a password reset, talk to the sysadmin quickly!<br><br>Have a nice day.' +
             '<br><br>The DeFinMa team', err => {