diff --git a/lib/lws-plat-win.c b/lib/lws-plat-win.c
index a79bcffa..8b481e79 100644
--- a/lib/lws-plat-win.c
+++ b/lib/lws-plat-win.c
@@ -1,4 +1,6 @@
+#ifndef _WINSOCK_DEPRECATED_NO_WARNINGS
 #define _WINSOCK_DEPRECATED_NO_WARNINGS
+#endif
 #include "private-libwebsockets.h"
 
 unsigned long long