Durandal has composition support for modal dialogs. I've been able to use them successfully, though there's a strange graphical artifact I cannot seem to eradicate. I'm pretty sure it's part of a div with class 'durandal-wrapper', though it's not present until runtime. How can I prevent this behavior without resorting to monkey patching some "overflow-y:blah;" onto an element after it's created and attached to the DOM by Durandal?