--- a/src/sbin/umount/umount.c
+++ b/src/sbin/umount/umount.c
@@ -401,7 +401,7 @@
 			free(orignfsdirname);
 			return (1);
 		}
-		clp->cl_auth = authsys_create_default();
+		clp->cl_auth = authunix_create_default();
 		try.tv_sec = 20;
 		try.tv_usec = 0;
 		clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir,