diff --git a/src/fd_util.c b/src/fd_util.c
index eb5c27df8..741a28ec3 100644
--- a/src/fd_util.c
+++ b/src/fd_util.c
@@ -39,6 +39,7 @@
 #include <errno.h>
 
 #ifdef WIN32
+#include <ws2tcpip.h>
 #include <winsock2.h>
 #else
 #include <sys/socket.h>