Specific outgoing IP for syncrepl

I've been using openldap's multi-master syncrepl based sync for years and it works great. But, I would like to be able to specify which IP on a multi-IP system syncrepl makes outgoing connections to other members of the sync cluster.

On my multi-IP servers I am able to get slapd to only bind to a specific IP with the appropriate -h option. That works fine. But, outgoing syncrepl connections come from the primary IP on the server.

Can anyone suggest a way to specify which IP syncrepl will use to make outgoing replication queries?