diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index 4b08086..2019d38 100644
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -33,6 +33,7 @@
 #include <stdio.h>
 #include <sddl.h>
 #include <shellapi.h>
+#include <mstcpip.h>
 
 #ifdef HAVE_VERSIONHELPERS_H
 #include <versionhelpers.h>