rpki-client and BLACKHOLE routes

Hi all,

fist of all, thank you for rpki-client, it's so easy to use it and to
get the job done.
I'm playing with rpki-client and denying ovs invalid statement and I've
seen that with default ovs config statement (deny from ebgp ovs invalid)
BLACKHOLE routes are blocked/invalid.

What is the right way to allow BLACKHOLE routes through rpki ? Or if
someone can give me a hint on what to do.

Thank you...