--- tests/keypairtest.c.orig	Sun Mar 18 00:31:20 2018
+++ tests/keypairtest.c	Sun Mar 18 00:31:33 2018
@@ -15,6 +15,10 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#ifdef _MSC_VER
+#define NO_REDEF_POSIX_FUNCTIONS
+#endif
+
 #include <sys/stat.h>
 
 #include <err.h>