1 files changed, 4 insertions, 0 deletions

diff --git a/toxcore/network.h b/toxcore/network.h
index b0d306e4..5e434c1a 100644
--- a/toxcore/network.h
+++ b/toxcore/network.h
@@ -44,6 +44,10 @@
 #include <windows.h>
 #include <ws2tcpip.h>
 
+#ifndef IPV6_V6ONLY
+#define IPV6_V6ONLY 27
+#endif
+
 typedef unsigned int sock_t;
 /* sa_family_t is the sockaddr_in / sockaddr_in6 family field */
 typedef short sa_family_t;