diff --git a/src/routes/cloudron.js b/src/routes/cloudron.js
index 83931bd00..29b264d66 100644
--- a/src/routes/cloudron.js
+++ b/src/routes/cloudron.js
@@ -106,7 +106,7 @@ function restore(req, res, next) {
 function dnsSetup(req, res, next) {
     assert.strictEqual(typeof req.body, 'object');
 
-    if (typeof req.body.provider !== 'string') return next(new HttpError(400, 'provider is required'));
+    if (typeof req.body.provider !== 'string' || !req.body.provider) return next(new HttpError(400, 'provider is required'));
     if (typeof req.body.domain !== 'string' || !req.body.domain) return next(new HttpError(400, 'domain is required'));
     if (typeof req.body.adminFqdn !== 'string' || !req.body.domain) return next(new HttpError(400, 'adminFqdn is required'));