diff --git a/setup-named-chroot.sh b/setup-named-chroot.sh
index 2704966..28134f5 100755
--- a/setup-named-chroot.sh
+++ b/setup-named-chroot.sh
@@ -1,22 +1,21 @@
 #!/bin/bash
 
+ROOTDIR="$1"
+CONFIG_FILES="${3:-/etc/named-chroot.files}"
 
 usage()
 {
   echo
   echo 'This script setups chroot environment for BIND'
-  echo 'Usage: setup-named-chroot.sh ROOTDIR <on|off> <config.files>'
+  echo 'Usage: setup-named-chroot.sh ROOTDIR <on|off> [chroot.files]'
 }
 
-if ! [ "$#" -eq 3 ]; then
+if ! [ "$#" -ge 2 -a "$#" -le 3 ]; then
   echo 'Wrong number of arguments'
   usage
   exit 1
 fi
 
-ROOTDIR="$1"
-CONFIG_FILES="$3"
-
 # Exit if ROOTDIR doesn't exist
 if ! [ -d "$ROOTDIR" ]; then
   echo "Root directory $ROOTDIR doesn't exist"
@@ -24,6 +23,12 @@ if ! [ -d "$ROOTDIR" ]; then
   exit 1
 fi
 
+if ! [ -r "$CONFIG_FILES" ]; then
+  echo "Files list $CONFIG_FILES doesn't exist" 2>&1
+  usage
+  exit 1
+fi
+
 dev_create()
 {
   DEVNAME="$ROOTDIR/dev/$1"