Does anyone know how to get jQuery's validator plugin to recognize input field names with special characters?

I have a framework that is generating a form field with these characters: []. Example:

<input type="text" name="user[firstname]" id="user-firstname" />

When using Jorn's plugin, the field is disregarded.

rules: { user[firstname]: "required"} is not recognized.

But, if I remove the [] from the field name and change the requirement accordingly, no problem.

Anyone know how to escape the square brackets?

Thanks!