diff --git a/sys/conf/files b/sys/conf/files
index ea7a8ec0125a..9a6dc0a79a8a 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -67,6 +67,7 @@ kern/kern_synch.c	standard
 kern/kern_sysctl.c	standard
 kern/kern_time.c	standard
 kern/kern_xxx.c		standard
+kern/md5c.c		optional md5
 kern/subr_diskslice.c	standard
 kern/subr_dkbad.c	standard
 kern/subr_log.c		standard