diff --git a/compat/win32/sys/poll.c b/compat/win32/sys/poll.c
index 7e74ebe59..708a6c9be 100644
--- a/compat/win32/sys/poll.c
+++ b/compat/win32/sys/poll.c
@@ -34,6 +34,9 @@
 
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 # define WIN32_NATIVE
+# if defined (_MSC_VER)
+#  define _WIN32_WINNT 0x0502
+# endif
 # include <winsock2.h>
 # include <windows.h>
 # include <io.h>