variable opt is not being used

[sofuxro]

I've using this setup:

gulp.src(config.html.jst_src)
        // Converts windows path to unix
        .pipe(slash())

        .pipe(jst_concat('templates.js', {
            renameKeys: ['^.*templates\/(.*).html$', '$1'],
            variable:   'data'
        }))

        .pipe(gulp.dest(config.html.jst_dest));

But my templates still look like this (still using the with):

this.JST = {"item_in_list": function(obj) {
obj || (obj = {});
var __t, __p = '', __e = _.escape, __j = Array.prototype.join;
function print() { __p += __j.call(arguments, '') }
with (obj) {