Error on --production build of Whatsapp clone

When I run my app (the whatsapp clone, with some added features) I get this error in console:

Error: [ng:areq] Argument 'LoginCtrl' is not a function, got undefined http://errors.angularjs.org/1.5.7/ng/areq?p0=LoginCtrl&p1=not%20a%20function%2C%20got%20undefined at 097ef93….js?meteor_js_resource=true:16 at ce (097ef93….js?meteor_js_resource=true:16) at fe (097ef93….js?meteor_js_resource=true:16) at a (097ef93….js?meteor_js_resource=true:17) at _.appendViewElement (097ef93….js?meteor_js_resource=true:32) at Object.render (097ef93….js?meteor_js_resource=true:32) at Object.init (097ef93….js?meteor_js_resource=true:32) at _.render (097ef93….js?meteor_js_resource=true:32) at _.register (097ef93….js?meteor_js_resource=true:32) at a (097ef93….js?meteor_js_resource=true:34)

The app is deployed to Heroku. The same thing happens when I deploy to galaxy.meteor.com, but there only for the mobile agent.

I have no idea how to go about this. I’ve updated meteor to 1.3.4 so far and also commented out every occurrence of LoginCtrl. If I do so it just displays another Controller in my error message.

Thanks in advance

EDIT: just downloaded the sample code from the tutorial, same problem when running meteor --production