#define ST(off) PL_stack_base[ax + (off)]
-#if defined(CYGWIN) && defined(USE_DYNAMIC_LOADING)
+#if defined(__CYGWIN__) && defined(USE_DYNAMIC_LOADING)
# define XS(name) __declspec(dllexport) void name(pTHXo_ CV* cv)
#else
# define XS(name) void name(pTHXo_ CV* cv)