WPF Flowdocument - can't left-align ListItem markers

Question

I've got a WPF FlowDocument with a list of MarkerType 'Upper Latin'. It's looking like this:

Notice that the list item alignment is on the periods after the marker, but since the text is variable width, the D, E, and F look silly. I would rather have the list markers be left aligned than right aligned, but I can't figure out how to do it. TextAlignment on the List or ListItem makes no difference.