rrd_init(rrd);
if (rdwr == RRD_READONLY) {
-#ifndef WIN32
+#if defined(WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
mode = "r";
#else
mode = "rb";
#endif
} else {
-#ifndef WIN32
+#if defined(WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
mode = "r+";
#else
mode = "rb+";