diff --git a/bind_change_ttl.sh b/bind_change_ttl.sh
index 3fdca1f..04eb60d 100755
--- a/bind_change_ttl.sh
+++ b/bind_change_ttl.sh
@@ -643,7 +643,10 @@ for _val in ${zonefiles_arr[@]} ; do
             if $(grep -q -E "\s+$TTL\s+IN\s+As+$_ipv4_address" $zone_file 2> /dev/null) ; then
                echo_skipped
             else
-               perl -i -n -p -e "s#([0-9]{2,5}\s+)?IN\s+A\s+$_ipv4_address#$TTL IN A     $_ipv4_address#" $zone_file > /dev/null 2>&1
+               # Note:
+               #   '\1${TTL}' in replace string DOES NOT work in perl regex.
+               #
+               sed -i -r -e"s#(\s+)([0-9]{2,5}\s+)?IN\s+A\s+$_ipv4_address#\1${TTL} IN A     $_ipv4_address#" $zone_file > /dev/null 2>&1
                if [ "$?" = "0" ]; then
                   echo_ok
                   _replaced=true
@@ -655,7 +658,7 @@ for _val in ${zonefiles_arr[@]} ; do
 
             if $_replaced && $IGNORE_ALT_HOSTNAMES ; then
                echononl "\t   Setting back hostnames containing \"-alt\".."
-               perl -i -n -p -e "s#^(.+(-alt).*)\s+$TTL\s+IN\s+A\s+$_ipv4_address#\1 IN A     $_ipv4_address#" $zone_file > /dev/null 2>&1
+               perl -i -n -p -e "s#^(.+(-alt)\s+)$TTL\s+IN\s+A\s+$_ipv4_address#\1IN A     $_ipv4_address#" $zone_file > /dev/null 2>&1
                if [ "$?" = "0" ]; then
                   echo_ok
                else
@@ -679,7 +682,10 @@ for _val in ${zonefiles_arr[@]} ; do
             if $(grep -q -E "\s+$TTL\s+IN\s+AAAA\s+$_ipv6_address" $zone_file 2> /dev/null) ; then
                echo_skipped
             else
-               perl -i -n -p -e "s#([0-9]{2,5}\s+)?IN\s+AAAA\s+$_ipv6_address#$TTL IN AAAA  $_ipv6_address#" $zone_file > /dev/null 2>&1
+               # Note:
+               #   '\1${TTL}' in replace string DOES NOT work in perl regex.
+               #
+               sed -i -r -e"s#(\s+)([0-9]{2,5}\s+)?IN\s+AAAA\s+$_ipv6_address#\1${TTL} IN AAAA  $_ipv6_address#" $zone_file > /dev/null 2>&1
                if [ "$?" = "0" ]; then
                   echo_ok
                   _replaced=true
@@ -690,7 +696,7 @@ for _val in ${zonefiles_arr[@]} ; do
             fi
             if $_replaced && $IGNORE_ALT_HOSTNAMES ; then
                echononl "\t   Setting back hostnames containing \"-alt\".."
-               perl -i -n -p -e "s#^(.+(-alt).*)\s+$TTL\s+IN\s+AAAA\s+$_ipv6_address#\1 IN AAAA  $_ipv6_address#" $zone_file > /dev/null 2>&1 
+               perl -i -n -p -e "s#^(.+(-alt)\s+)$TTL\s+IN\s+AAAA\s+$_ipv6_address#\1IN AAAA  $_ipv6_address#" $zone_file > /dev/null 2>&1 
                if [ "$?" = "0" ]; then
                   echo_ok
                else