[Haskell-cafe] Error when building executable with profiling enabled

Hello, i have an executable where i want to run profiling on. I do: ghc --make -prof -auto-all -fth Custom.hs but it does not built and the output is: bench\HLogo\Custom\Custom.hs:1:1: Dynamic linking required, but this is a non-standard build (eg. prof). You need to build the program twice: once the normal way, and then in the desired way using -osuf to set the object file suffix. I tried googling on the error with no success. What can I do to compile this file for profiling? Cheers, Nikos