route generator with prefix doesn't add prefix in L5

[subdesign]

So in my resource controller, where I return the Datatable::collection(), the route() doesn't add the group prefix into the final route. Very strange, yeah. Outside of this, in different controller dumping the route works well. If my group prefix is 'admin' and inside that my route is 'users/{id}/edit' as 'users.edit' the result is following:

route('users.edit', 1) -> users/1/edit
URL::route('users.edit', 1) -> users/1/edit

and it should be: admin/users/1/edit .. it was working in the Laravel 4 version. using develop branch for L5 in this case thanks