diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index e96368ca..2d3ba623 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -1038,6 +1038,23 @@ do_ifconfig_ipv6(struct tuntap *tt, const char *ifname, int tun_mtu,
     openvpn_execve_check(&argv, es, S_FATAL,
                          "generic BSD ifconfig inet6 failed");
 
+#if defined(TARGET_FREEBSD) && __FreeBSD_version >= 1200000
+    /* FreeBSD 12 grew some sort of race condition where sometimes
+     * the IPv6 side of a tun interface is stuck in "IFDISABLED"
+     * in "ifconfig tun0" output, and the assigned IPv6 address is not
+     * working ("tentative").  Workaround in here, for now.
+     *
+     * the sleep is needed because there is a race condition, so turning
+     * it off immediately can lead to "kernel turns it on again, stuck!!"
+     */
+    sleep(1);
+    argv_printf(&argv, "%s %s inet6 -ifdisabled", IFCONFIG_PATH, ifname);
+    argv_msg(M_INFO, &argv);
+
+    openvpn_execve_check(&argv, es, S_FATAL,
+                         "FreeBSD BSD 'ifconfig inet6 -ifdisabled' failed");
+#endif
+
 #if defined(TARGET_OPENBSD) || defined(TARGET_NETBSD) \
     || defined(TARGET_DARWIN)
     /* and, hooray, we explicitly need to add a route... */