Can only call _ensureIndex on server collections

I’ve added this index at the collections file, so I can do geo queries.:
Rooms._ensureIndex({geoLocation: “2dsphere”});
It works fine on localhost but on production (meteor --production) i get:
Can only call _ensureIndex on server collections
Does it mean that i must move that collection to the server?

this line only on the server is enough.

Minimongo has no support for indexes, so this function is not available on the client. However, there shouldn’t be a difference between development and production in this behavior, so that seems weird.

Just to clarify, Now when the line above is on the server, I get no error. Before it gave the ‘broken route’ error page and only on the production. Weird or not i don’t know.
So, no alert now, but i guess it won’t work on the client that way or another.
so should I implement a Js function to do the distance sorting?