Trouble compiling Bro release 0.8a48 on OpenBSD3.3

I get the following errors when I try to compile Bro on
OpenBSD 3.3.

gcc -I. -Ilibedit -O -c nb_dns.c
nb_dns.c:81: `NS_MAXDNAME' undeclared here (not in a function)

A work-around for this is to edit config.h and #undef HAVE_NB_DNS,
and also remove nb_dns.o from the generated Makefile. (I have the same
problem building on Mac OS X; and also have to turn off HAVE_READLINE.)
I haven't figured out how to get autoconf to do this automagically - if
someone could contribute that, that would be great.