https request from heroku

I am tying to get data from vk.com api via https protocol. like this (api vk docs):

var https = require('https');

https.get('https://api.vk.com/method/users.get?access_token=' + global['access_token'], function (d) {
  var chunk = '';
  d.on('data', function (data) {
    chunk += data;
  });

  d.on('end', function () {
    console.log(chunk);
  });
}).on('error', function (e) {
  console.error(e);
});

but in heroku logs I see

Error: Protocol:https: not supported.

So, how can I get this data? My app work in http protocol, this is config:

var express = require('express'),
  routes = require('./routes');

var app = express();

    app.configure(function () {
      app.set('port', process.env.PORT || 3000);
      app.set('views', __dirname + '/views');
      app.set('view engine', 'jade');
      app.use(express.favicon());
      app.use(express.logger('dev'));
      app.use(express.bodyParser());
      app.use(express.methodOverride());
      app.use(app.router);
      app.use(express.static(path.join(__dirname, 'public')));
    });

    app.configure('development', function () {
      app.use(express.errorHandler());
    });

    app.get('/', routes.index);

    http.createServer(app).listen(app.get('port'), function () {
      console.log("Express server listening on port " + app.get('port'));
    });