diff --git a/mud b/mud
index 04c8495..f0ad4bb 160000
--- a/mud
+++ b/mud
@@ -1 +1 @@
-Subproject commit 04c8495fe6ec34b984a47a66d7c77eb385c8f26d
+Subproject commit f0ad4bbdd39e887325bc015f856015ae032ed01b
diff --git a/src/main.c b/src/main.c
index 6e110a7..8f21cfb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -244,6 +244,9 @@ int main (int argc, char **argv)
 
     long time_tolerance = 0;
 
+    int v4 = 1;
+    int v6 = 1;
+
     struct option opts[] = {
         { "host",           &host,           option_str    },
         { "port",           &port,           option_str    },
@@ -255,6 +258,8 @@ int main (int argc, char **argv)
         { "statefile",      &statefile,      option_str    },
         { "timeout",        &gt.timeout,     option_long   },
         { "time-tolerance", &time_tolerance, option_long   },
+        { "v4only",         NULL,            option_option },
+        { "v6only",         NULL,            option_option },
         { "version",        NULL,            option_option },
         { NULL },
     };
@@ -267,6 +272,17 @@ int main (int argc, char **argv)
         return 0;
     }
 
+    if (option_is_set(opts, "v4only"))
+        v6 = 0;
+
+    if (option_is_set(opts, "v6only"))
+        v4 = 0;
+
+    if (!v4 && !v6) {
+        gt_log("v4only and v6only are both set\n");
+        return 1;
+    }
+
     if (!option_is_set(opts, "keyfile")) {
         gt_log("keyfile option must be set\n");
         return 1;
@@ -299,7 +315,7 @@ int main (int argc, char **argv)
     if (gt_setup_secretkey(keyfile))
         return 1;
 
-    struct mud *mud = mud_create(bind_port);
+    struct mud *mud = mud_create(bind_port, v4, v6);
 
     if (!mud) {
         gt_log("couldn't create mud\n");