Index: head/sys/fs/nfs/nfs.h
===================================================================
--- head/sys/fs/nfs/nfs.h
+++ head/sys/fs/nfs/nfs.h
@@ -252,6 +252,11 @@
 	int		nid_namelen;	/* and its length */
 };
 
+struct nfsuserd_args {
+	sa_family_t	nuserd_family;	/* Address family to use */
+	u_short		nuserd_port;	/* Port# */
+};
+
 struct nfsd_clid {
 	int		nclid_idlen;	/* Length of client id */
 	u_char		nclid_id[NFSV4_OPAQUELIMIT]; /* and name */
Index: head/sys/fs/nfs/nfs_commonport.c
===================================================================
--- head/sys/fs/nfs/nfs_commonport.c
+++ head/sys/fs/nfs/nfs_commonport.c
@@ -631,14 +631,24 @@
 		goto out;
 	} else if (uap->flag & NFSSVC_NFSUSERDPORT) {
 		u_short sockport;
+		struct nfsuserd_args nargs;
 
-		if ((uap->flag & NFSSVC_NEWSTRUCT) == 0)
+		if ((uap->flag & NFSSVC_NEWSTRUCT) == 0) {
 			error = copyin(uap->argp, (caddr_t)&sockport,
 			    sizeof (u_short));
-		else
-			error = ENXIO;
+			if (error == 0) {
+				nargs.nuserd_family = AF_INET;
+				nargs.nuserd_port = sockport;
+			}
+		} else {
+			/*
+			 * New nfsuserd_args structure, which indicates
+			 * which IP version to use along with the port#.
+			 */
+			error = copyin(uap->argp, &nargs, sizeof(nargs));
+		}
 		if (!error)
-			error = nfsrv_nfsuserdport(sockport, p);
+			error = nfsrv_nfsuserdport(&nargs, p);
 	} else if (uap->flag & NFSSVC_NFSUSERDDELPORT) {
 		nfsrv_nfsuserddelport();
 		error = 0;
Index: head/sys/fs/nfs/nfs_commonsubs.c
===================================================================
--- head/sys/fs/nfs/nfs_commonsubs.c
+++ head/sys/fs/nfs/nfs_commonsubs.c
@@ -42,6 +42,7 @@
  * copy data between mbuf chains and uio lists.
  */
 #ifndef APPLEKEXT
+#include "opt_inet.h"
 #include "opt_inet6.h"
 
 #include <fs/nfs/nfsport.h>
@@ -3504,10 +3505,16 @@
  * Set the port for the nfsuserd.
  */
 APPLESTATIC int
-nfsrv_nfsuserdport(u_short port, NFSPROC_T *p)
+nfsrv_nfsuserdport(struct nfsuserd_args *nargs, NFSPROC_T *p)
 {
 	struct nfssockreq *rp;
+#ifdef INET
 	struct sockaddr_in *ad;
+#endif
+#ifdef INET6
+	struct sockaddr_in6 *ad6;
+	const struct in6_addr in6loopback = IN6ADDR_LOOPBACK_INIT;
+#endif
 	int error;
 
 	NFSLOCKNAMEID();
@@ -3527,15 +3534,37 @@
 	rp->nr_soproto = IPPROTO_UDP;
 	rp->nr_lock = (NFSR_RESERVEDPORT | NFSR_LOCALHOST);
 	rp->nr_cred = NULL;
-	rp->nr_nam = malloc(sizeof(*rp->nr_nam), M_SONAME, M_WAITOK | M_ZERO);
-	NFSSOCKADDRSIZE(rp->nr_nam, sizeof (struct sockaddr_in));
-	ad = NFSSOCKADDR(rp->nr_nam, struct sockaddr_in *);
-	ad->sin_family = AF_INET;
-	ad->sin_addr.s_addr = htonl((u_int32_t)0x7f000001);	/* 127.0.0.1 */
-	ad->sin_port = port;
 	rp->nr_prog = RPCPROG_NFSUSERD;
+	error = 0;
+	switch (nargs->nuserd_family) {
+#ifdef INET
+	case AF_INET:
+		rp->nr_nam = malloc(sizeof(struct sockaddr_in), M_SONAME,
+		    M_WAITOK | M_ZERO);
+ 		ad = (struct sockaddr_in *)rp->nr_nam;
+		ad->sin_len = sizeof(struct sockaddr_in);
+ 		ad->sin_family = AF_INET;
+		ad->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+		ad->sin_port = nargs->nuserd_port;
+		break;
+#endif
+#ifdef INET6
+	case AF_INET6:
+		rp->nr_nam = malloc(sizeof(struct sockaddr_in6), M_SONAME,
+		    M_WAITOK | M_ZERO);
+		ad6 = (struct sockaddr_in6 *)rp->nr_nam;
+		ad6->sin6_len = sizeof(struct sockaddr_in6);
+		ad6->sin6_family = AF_INET6;
+		ad6->sin6_addr = in6loopback;
+		ad6->sin6_port = nargs->nuserd_port;
+		break;
+#endif
+	default:
+		error = ENXIO;
+ 	}
 	rp->nr_vers = RPCNFSUSERD_VERS;
-	error = newnfs_connect(NULL, rp, NFSPROCCRED(p), p, 0);
+	if (error == 0)
+		error = newnfs_connect(NULL, rp, NFSPROCCRED(p), p, 0);
 	if (error) {
 		free(rp->nr_nam, M_SONAME);
 		nfsrv_nfsuserd = 0;
Index: head/sys/fs/nfs/nfs_var.h
===================================================================
--- head/sys/fs/nfs/nfs_var.h
+++ head/sys/fs/nfs/nfs_var.h
@@ -136,7 +136,7 @@
     NFSPROC_T *);
 int nfsrv_checkgetattr(struct nfsrv_descript *, vnode_t,
     struct nfsvattr *, nfsattrbit_t *, NFSPROC_T *);
-int nfsrv_nfsuserdport(u_short, NFSPROC_T *);
+int nfsrv_nfsuserdport(struct nfsuserd_args *, NFSPROC_T *);
 void nfsrv_nfsuserddelport(void);
 void nfsrv_throwawayallstate(NFSPROC_T *);
 int nfsrv_checksequence(struct nfsrv_descript *, uint32_t, uint32_t *,