[gentoo-amd64] revert to the stable version of a specific package

[Thanasis]

I want to revert to the stable version of a specific package
(sys-fs/cryptsetup-1.0.6-r2), while in /etc/make.conf I have
ACCEPT_KEYWORDS="~amd64".
For that I have put in /etc/portage/package.keywords:
sys-fs/cryptsetup amd64
and then I run
emerge -1 =sys-fs/cryptsetup-1.0.6-r2
Is that the way I should go?
Because I tried it, but when I run
emerge -DNu world
it still wants to upgrade to sys-fs/cryptsetup-1.1.0.