Hi. I have composed a patch that implements Foreign.C.String according to Foreign Function Interface Addendum, i.e. C strings are treated as they are encoded with the current locale. Search "Locale.hs" in the patch for further directions. Ask if you do not know how to build a patched version of the "base" library. http://www.beroal.in.ua/prg/haskell/locale.patch -- Best regards, Roman Beslik.