meteor-scss: [SASS] Application broken since v.3.3

I’m using SASS (not SCSS) and having this error on all files that has an import:

   While processing files with fourseven:scss (for target web.browser):
   /main.sass: Scss compiler error: invalid top-level expression

Or this:

   /client/templates/components/header/header.sass: Scss compiler error: top-level @import directive must be
   terminated by ';'

It seems that it’s trying to compile my .sass as an .scss.

REPRODUCTION:

main.sass

@import "teste"

_teste.sass THIS IS NOT WORKING ANYMORE

body
  background: red

_teste.sass this works, but shouldn’t because it’s a .sass

body {
  background: red;
}