diff --git a/src/net_socket.c b/src/net_socket.c
index 753229b4..2ed685da 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -102,6 +102,11 @@ int setup_listen_socket(const sockaddr_t *sa)
 	option = 1;
 	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+	if(sa->sa.sa_family == AF_INET6)
+		setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+#endif
+
 	if(get_config_string
 	   (lookup_config(config_tree, "BindToInterface"), &iface)) {
 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
@@ -181,6 +186,11 @@ int setup_vpn_in_socket(const sockaddr_t *sa)
 	option = 1;
 	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+	if(sa->sa.sa_family == AF_INET6)
+		setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+#endif
+
 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 	{
 		bool choice;
@@ -326,6 +336,12 @@ begin:
 		goto begin;
 	}
 
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+	int option = 1;
+	if(c->address.sa.sa_family == AF_INET6)
+		setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+#endif
+
 	/* Optimize TCP settings */
 
 	configure_tcp(c);