Nodeunit done() take effect after delay

I'm trying to write test for my nodejs module, and in this context i use code like this:

var http = require('http');
exports.asyncTest = function(test) {
    http.get("http://www.google.com/", function(res) {
        test.ok(true, "ok");
        test.done();
    }).on('error', function(e) {
        test.ok(false, "fail");
        test.done();
    });
};

Test result is correct, but i get result only after ~5 minutes delay. Whats wrong with this code or its just nodeunit feature/bug?