# define XS(name) EXPORT_C void name(pTHX_ CV* cv)
#endif
#ifndef XS
-# if defined(HASATTRIBUTE)
-# define XS(name) void name(pTHX_ CV* cv __attribute__((unused)))
+# ifdef HASATTRIBUTE_UNUSED
+# define XS(name) void name(pTHX_ CV* cv __attribute__unused__)
# else
# define XS(name) void name(pTHX_ CV* cv)
# endif