Compile error under FreeBSD 6 + GCC 3.4.4

If I try compile under GCC 3.4.4 on FreeBSD 6

The following error:

Source/util.h:10:21: iconv.h: No such file or directory

and indeed no iconv.h, where to get it?

OK, sorry, I first thought it was NSIS Source...

/usr/include/sys/iconv.h
/usr/local/include/iconv.h

I will puzzle on...
FYI: under Linux I had no problume getting makensis to compile and work. Anyone lucky enought to get a successful build under FreeBSD ?