diff --git a/libexec/rc/rc.d/tmp b/libexec/rc/rc.d/tmp
--- a/libexec/rc/rc.d/tmp
+++ b/libexec/rc/rc.d/tmp
@@ -40,10 +40,16 @@
 
 mount_tmpmfs()
 {
-	if ! /bin/df /tmp | grep -q "^/dev/md[0-9].* /tmp"; then
-		mount_md ${tmpsize} /tmp "${tmpmfs_flags}"
-		chmod 01777 /tmp
-	fi
+	while read line; do
+		case $line in
+		/dev/md[0-9]*\ /tmp)
+			return;;
+		esac
+	done <<*EOF
+$(df /tmp)
+*EOF
+	mount_md ${tmpsize} /tmp "${tmpmfs_flags}"
+	chmod 01777 /tmp
 }
 
 # If we do not have a writable /tmp, create a memory
@@ -52,7 +58,8 @@
 #
 case "${tmpmfs}" in
 [Aa][Uu][Tt][Oo])
-	if _tmpdir=$(mktemp -d -q /tmp/.diskless.XXXXXX); then
+	_tmpdir=/tmp/.diskless.$(dd if=/dev/random bs=32 count=1 2>/dev/null | sha256)
+	if mkdir $_tmpdir; then
 		rmdir ${_tmpdir}
 	else
 		if [ -h /tmp ]; then