Two-way binding in custom component not working

I've created a component like this:

templates/components/files-dropzone.hbs

<p>Awesome text</p>
<textarea id="drop-textarea" rows="10" cols="50">
  {{value}}
</textarea>

components/files-dropzone.js

import Ember from 'ember';

export default Ember.Component.extend({
  value: ''
})

I'm using this component like this in another template:

<div class="large-7 columns padding-left-reset"
  {{files-dropzone value=body}}
</div>

While the textarea contains the correct value for body when I load the page it doesn't bind it. I'm observing body and it doesn't change when I change the text inside the textarea.

What am I doing wrong?