failing buster.js setUp async delay before testing

buster-test.js

buster.testCase('dummy async test', {

    setUp: function(done) {
        var self = this;
        this.yes = false;
        setTimeout(function() {
            self.yes = true;
            done();
        }, 3000);
    },

    'should pass after setup returns': function() {
        buster.assert.isTrue(this.yes);
    }

});

the above fails if the setTimeout is anything over 250ms.