Hi All, I want to revive and push forward a change first proposed in 2014 for an API change in the Win32 package. The discussion at that time took place here https://github.com/haskell/win32/issues/24 In short, In the Windows API it is common that when a function accepts a pointer to something, that NULL also be valid and defaults to some action. Such an example is the FindWindow call. https://msdn.microsoft.com/en-us/library/windows/desktop/ms633499(v=vs.85).a... HWND WINAPI FindWindow( _In_opt_ LPCTSTR lpClassName, _In_opt_ LPCTSTR lpWindowName ); In this case, both the ClassName and the WindowName are allowed to be NULL. The Haskell binding to this function is findWindow :: String -> String -> IO (Maybe HWND). So we've lost the ability to use the default parameters. The proposal is to change such functions to accept Maybe: findWindow :: String -> String -> IO (Maybe HWND) becomes findWindow :: Maybe String -> Maybe String -> IO (Maybe HWND) Which also would more accurately match the original API. This is of course a backwards incompatible change. Any objections to this change? Thanks, Tamar