diff --git a/src/window.c b/src/window.c
index 1837838..84de2e1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -3260,6 +3260,11 @@ configureXWindow (CompWindow      *w,
     if (valueMask & CWBorderWidth)
        w->serverBorderWidth = xwc->border_width;
 
+    /* FIXME: assuming StackMode = Above is correct for the moment, but
+       may break later */
+    if (valueMask & CWSibling)
+       restackWindow (w, xwc->sibling);
+
     if (valueMask)
     {
        XConfigureWindow (w->screen->display->display, w->id, valueMask, xwc);