diff --git a/engine/common/plugin.c b/engine/common/plugin.c
index 02f7f7ef1..80f570c9c 100644
--- a/engine/common/plugin.c
+++ b/engine/common/plugin.c
@@ -793,6 +793,10 @@ int Plug_Con_RenameSub(void *offset, unsigned int mask, const long *arg)
 #define EADDRNOTAVAIL	WSAEADDRNOTAVAIL
 
 #define qerrno WSAGetLastError()
+
+#ifdef IPPROTO_IPV6
+#include <ws2tcpip.h>
+#endif
 #else