diff --git a/extra/x/widgets/wm/frame/frame.factor b/extra/x/widgets/wm/frame/frame.factor
index 4e3b4e7c93..b75671fa3c 100755
--- a/extra/x/widgets/wm/frame/frame.factor
+++ b/extra/x/widgets/wm/frame/frame.factor
@@ -4,6 +4,7 @@ USING: kernel io combinators namespaces quotations arrays sequences
        x11.xlib x11.constants
        mortar mortar.sugar slot-accessors
        geom.rect
+       math.bitfields
        x x.gc x.widgets
        x.widgets.button
        x.widgets.wm.child