diff --git a/os/xserver_poll.c b/os/xserver_poll.c
index f152cda21..1927dfa10 100644
--- a/os/xserver_poll.c
+++ b/os/xserver_poll.c
@@ -84,6 +84,10 @@
 #include <string.h>                          /* string functions */
 #include "xserver_poll.h"
 
+#if defined(WIN32) && !defined(__CYGWIN__)
+#include <X11/Xwinsock.h>
+#endif
+
 /*---------------------------------------------------------------------------*\
 				  Macros
 \*---------------------------------------------------------------------------*/