Getting attribute of a parent node

I am trying to use

$(this).parentNode.attr('data-element')

which should return 0 - 5 in string but it just won't work. I am using it in a function like this

$('.someClass').each(function(){
    $(this).html(SomeFunction('SomeString', $(this).parentNode.attr('data-element')));
});

All the elements with class 'someClass' have a parentNode

<li class="element" data-element: 1 (or any number from 0 to 5 (including))> </li>

and I have no idea where is the mistake. What am I doing wrong?

--David