#ifdef HAS_SETLINEBUF
#define PerlIO_setlinebuf(f) setlinebuf(f);
#else
-#define PerlIO_setlinebuf(f) setvbuf(f, Nullch, _IOLBF, 0);
+# ifdef CYGWIN
+# define PerlIO_setlinebuf(f)
+# else
+# define PerlIO_setlinebuf(f) setvbuf(f, Nullch, _IOLBF, 0);
+# endif
#endif
/* Now our interface to Configure's FILE_xxx macros */