diff --git a/include/sys/event.h b/include/sys/event.h
index d080e705..5d9e6189 100644
--- a/include/sys/event.h
+++ b/include/sys/event.h
@@ -257,7 +257,7 @@ extern "C" {
 
 #ifdef _WIN32
 
-#if (_MSC_VER < 1900)
+#if defined (_MSC_VER) && (_MSC_VER < 1900)
 struct timespec {
     time_t  tv_sec;
     long    tv_nsec;
diff --git a/src/windows/platform.h b/src/windows/platform.h
index 104b8205..e518825e 100644
--- a/src/windows/platform.h
+++ b/src/windows/platform.h
@@ -18,7 +18,9 @@
 #define  _KQUEUE_WINDOWS_PLATFORM_H
 
 /* Require Windows Server 2003 or later */
+#if WINVER < 0x0502
 #define WINVER 0x0502
+#endif
 #ifndef _WIN32_WINNT
 #define _WIN32_WINNT 0x0502
 #endif
@@ -28,6 +30,7 @@
 #include <io.h>
 #include <malloc.h>
 #include <sys/stat.h>
+#include <errno.h>
 
 #include "../common/queue.h"