diff --git a/src/mailer.js b/src/mailer.js
index ec050b8c6..a85001e18 100644
--- a/src/mailer.js
+++ b/src/mailer.js
@@ -24,6 +24,7 @@ exports = module.exports = {
     FEEDBACK_TYPE_TICKET: 'ticket',
     FEEDBACK_TYPE_APP_MISSING: 'app_missing',
     FEEDBACK_TYPE_APP_ERROR: 'app_error',
+    FEEDBACK_TYPE_UPGRADE_REQUEST: 'upgrade_request',
     sendFeedback: sendFeedback,
 
     _getMailQueue: _getMailQueue,
@@ -417,6 +418,7 @@ function sendFeedback(user, type, subject, description) {
     assert(type === exports.FEEDBACK_TYPE_TICKET ||
         type === exports.FEEDBACK_TYPE_FEEDBACK ||
         type === exports.FEEDBACK_TYPE_APP_MISSING ||
+        type === exports.FEEDBACK_TYPE_UPGRADE_REQUEST ||
         type === exports.FEEDBACK_TYPE_APP_ERROR);
 
     var mailOptions = {
diff --git a/src/routes/cloudron.js b/src/routes/cloudron.js
index 9cef3060e..730950067 100644
--- a/src/routes/cloudron.js
+++ b/src/routes/cloudron.js
@@ -134,7 +134,8 @@ function feedback(req, res, next) {
     if (req.body.type !== mailer.FEEDBACK_TYPE_FEEDBACK &&
         req.body.type !== mailer.FEEDBACK_TYPE_TICKET &&
         req.body.type !== mailer.FEEDBACK_TYPE_APP_MISSING &&
-        req.body.type !== mailer.FEEDBACK_TYPE_APP_ERROR) return next(new HttpError(400, 'type must be either "ticket", "feedback" or "app_missing" or "app_error"'));
+        req.body.type !== mailer.FEEDBACK_TYPE_UPGRADE_REQUEST &&
+        req.body.type !== mailer.FEEDBACK_TYPE_APP_ERROR) return next(new HttpError(400, 'type must be either "ticket", "feedback", "app_missing", "app_error" or "upgrade"'));
     if (typeof req.body.subject !== 'string' || !req.body.subject) return next(new HttpError(400, 'subject must be string'));
     if (typeof req.body.description !== 'string' || !req.body.description) return next(new HttpError(400, 'description must be string'));