js-yaml freezes when trying to parse a multi line string

I am having a problem when trying to use js-yaml in my node.js application.

My code (in coffeescript, but I believe it's readable for ordinary javascript users) looks like this:

loadConfig: (path, callback = false) =>
  fs.readFile path, 'utf8', (err, data) =>
    console.log data
    throw err if err
    @config = yaml.eval data #freezes here as mentioned below
    console.log @config

When trying to parse a yaml config file like this:

foo: bar

Everything goes as expected. But when I change it to look like this:

foo:
  bar: baz

or even:

# bla bla
foo: bar

my function freezes without any errors. The second console.log isn't reached. After some time spent frozen, the app kills itself.

I tried changing line ending formats to no avail. Does anyone know what would be the cause of the problem or how to debug/troubleshoot it?