/F revealed that ShellExecute() only requires shellapi.h, not the
full-blown windows.h, so changed accordingly.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8a419c3..47bea6f 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -217,8 +217,9 @@
#include <io.h>
#include <process.h>
#include "osdefs.h"
-/* We don't want WIN32_LEAN_AND_MEAN here -- we need ShellExecute(). */
+#define WIN32_LEAN_AND_MEAN
#include <windows.h>
+#include <shellapi.h> /* for ShellExecute() */
#define popen _popen
#define pclose _pclose
#endif /* _MSC_VER */