module-deps and through not working

gistfile1.js

// outputs everything

var mdeps = require('module-deps');

mdeps(__dirname + '/index.js')
  .on('error', console.error)
  .on('data', console.log);

gistfile2.js

// outputs nothing

var mdeps = require('module-deps');
var through = require('through');

mdeps(__dirname + '/index.js')
  .on('error', console.error)
  .pipe(through(console.log));