inc/dec workspace

I'd like to be able to "move" (rearrange) workspaces. To do so, I hadded
the following code to cfg_ioncore.lua:

defbindings("WScreen", {
-- Stuff
     bdoc("Move current workspace left/right."),
     kpress(META.."Shift+comma",  "WScreen.dec_index(_, _sub)", "_sub:non-nil"),
     kpress(META.."Shift+period", "WScreen.inc_index(_, _sub)", "_sub:non-nil"),
-- Stuff
})

This does what I want, except for the fact that it doesn't update the
statusbar. (I use statusbar_workspace.lua and have
"template=%workspace_pager" set). The statusbar does get updated
correctly whenever I next do anything that would normally update it.

How would I get the statusbar to update after rearranging my workspace?

Thanks much!