Qt 5.1 on Linux/X11 ignores xkb keyboard layout

I use a modified version of the Dvorak keyboard layout on my system. I have it configured with xkb (using "xkbcomp $HOME/us-dvorak-slate.xkb $DISPLAY"; xkb config can be found at http://dotfiles.g33xnexus.com/whitelynx/us-dvorak-slate.xkb ), but anything built against Qt 5.1 acts as if the keyboard is still in QWERTY.

I've verified that this issue exists in Qt Creator, qmlscene, some C++/QML apps I've been working on, and several of the Qt examples, on both the "Qt 5.1.0 for Linux 64-bit" download from http://qt-project.org/downloads, and the Qt 5 packages in ArchLinux. This wasn't a problem on Qt 5.0.

I found QTBUG-31527, which that seems to suggest that using xkb as opposed to xmodmap should fix the issue... but I've been using xkb instead of xmodmap for quite a while now, and Qt 5.1 still ignores my layout.