[Xmonad] Question about window ordering

I just installed the Tabbed extension, and it's great (thanks, David!). Now I can probably ditch ion for good. However, the tabs revealed to me something I hadn't noticed before: that a new window gets placed to the left of the currently selected window. Is there any way to make the new window come up to the right of the currently selected window, which I find more intuitive? Thanks, Mike