diff --git a/include/paths.h b/include/paths.h
index 86900664230b..f8861ea4e5a8 100644
--- a/include/paths.h
+++ b/include/paths.h
@@ -89,6 +89,7 @@
 #define	_PATH_SENDMAIL	"/usr/sbin/sendmail"
 #define	_PATH_SHELLS	"/etc/shells"
 #define	_PATH_TTY	"/dev/tty"
+#define	_PATH_TUNEFS	"/sbin/tunefs"
 #define	_PATH_UNIX	"don't use _PATH_UNIX"
 #define	_PATH_UFSSUSPEND	"/dev/ufssuspend"
 #define	_PATH_VI	"/usr/bin/vi"
@@ -138,6 +139,8 @@ __END_DECLS
 #define	_PATH_REBOOT	"/rescue/reboot"
 #undef	_PATH_RM
 #define	_PATH_RM	"/rescue/rm"
+#undef	_PATH_TUNEFS
+#define	_PATH_TUNEFS	"/rescue/tunefs"
 #undef	_PATH_VI
 #define	_PATH_VI	"/rescue/vi"
 #undef	_PATH_WALL
diff --git a/sbin/mdmfs/mdmfs.c b/sbin/mdmfs/mdmfs.c
index 93fa9e8ff0c0..69149b3fb465 100644
--- a/sbin/mdmfs/mdmfs.c
+++ b/sbin/mdmfs/mdmfs.c
@@ -104,7 +104,7 @@ main(int argc, char **argv)
 	bool detach, softdep, autounit, newfs;
 	const char *mtpoint, *size_arg, *skel, *unitstr;
 	char *p;
-	int ch, idx;
+	int ch, idx, rv;
 	void *set;
 	unsigned long ul;
 
@@ -357,6 +357,13 @@ main(int argc, char **argv)
 			do_mdconfig_attach(mdconfig_arg, mdtype);
 		if (newfs)
 			do_newfs(newfs_arg);
+		if (!softdep) {
+			rv = run(NULL, "%s %s /dev/%s%d", _PATH_TUNEFS,
+			    "-n disable", mdname, unit);
+			if (rv)
+				errx(1, "tunefs exited %s %d", run_exitstr(rv),
+				    run_exitnumber(rv));
+		}
 		do_mount_md(mount_arg, mtpoint);
 	}