--- modules/freebsd/vmmemctl/os.c.orig	2013-09-23 15:51:10 UTC

+++ modules/freebsd/vmmemctl/os.c

@@ -827,7 +891,11 @@ vmmemctl_init_sysctl(void)

    oid =  sysctl_add_oid(NULL, SYSCTL_STATIC_CHILDREN(_vm), OID_AUTO,

                          BALLOON_NAME, CTLTYPE_STRING | CTLFLAG_RD,

                          0, 0, vmmemctl_sysctl, "A",

-                         BALLOON_NAME_VERBOSE);

+                         BALLOON_NAME_VERBOSE

+#if __FreeBSD_version >= 1200019

+                         , NULL

+#endif

+                        );

 }