Get all parents that don't have a child with a certain class

I want to select all div's of parents using jQuery, that don't have children with the class locked

Example code:

<div class='myparent'>
    <div class='mychild locked'></div>
</div>
<div class='myparent'>
    <div class='mychild locked'></div>
</div>
<div class='myparent'>
    <div class='mychild'></div>
</div>

I feel like I'm really close:

$('div.myparent:not(:has(div[class=locked]))')

But that does not work.