Linking stage 2 compiler with non-threaded RTS using Make?

Anyone know how to link stage 2 with non-threaded RTS using Make build system? There's a variable GhcThreaded, but setting it "NO" makes no difference, stage 2 compiler is still threaded. So far the only way I could find is to redirect build system output to a file, find the step that linked ghc-stage2, repeat that command but without -threaded. It's really painful as I have to repeat this step after every rebuild. Any tips? Thanks, Ömer