I'm experimenting creating a Cabal script on Windows that installs a module that refers to some DLLs (freetype, png, ...) via C wrappers When configuring, building, and installing using cabal, a test program that uses this installed module runs fine when compiled with GHC --make, but fails miserably when run with RUNGHC (or GHCi) The first thing I noticed is that RUNGHC looks for a DLL called "png.dll" (which it doesn't find and then bails out with an error), while the executable build with GHC uses the correct "libpng3.dll". When I rename the libpng3.dll into png.dll, RUNGHC goes a bit further but then fails with an "unknown symbol". Obviously I did something wrong in my Cabal script, but I have no idea what it is. There seems to be a big difference when it comes to linking between of GHCi and GHC . Any guidelines on what to do in cases like the one above? I really like to use the interpreter because it provides much shorter turnaround times, and things like this stop me from using it. Thanks, Peter