I'll try to make it short. I'm developping a package wich imports C functions. the fact is that when I try to compile if I call the compiler in the usual way, using -package and -llib it gives an undefined reference error... For example if I use: $ghc -package PKGname-PKGversion -fffi -o main Main.hs -llib it gives an error message (undefined references of objects from PKG to functions in lib) but if I use: $ghc -fffi -o main Main.hs -llib /path/to/PKGlib.a it compiles correctly. and also when I do: $ghc -package PKGname-PKGversion -fffi -o main Main.hs /path/to/lib.a it compiles correctly. I know that it is surely my mistake but I didn't find anything helpful in docummentation or in FFI list. I know that I should send this message to ffi mailing list but it is kind of stopped and I think I'll get my answers here... Thank you for the atention.