https://bugs.openldap.org/show_bug.cgi?id=9847
--- Comment #6 from Howard Chu hyc@openldap.org ---
this sounds to me like an OS bug either in their kernel or their manpage.
"Their" meaning OpenBSD.
Since you submitted that patch to FreeBSD: did you verify that it is actually misbehaving on FreeBSD first? We've seen no bug reports about it and this support has been in the tree for a couple years already.