diff --git a/debian/miniupnpd.postinst b/debian/miniupnpd.postinst
index 1579dd9..bd7305c 100644
--- a/debian/miniupnpd.postinst
+++ b/debian/miniupnpd.postinst
@@ -13,7 +13,7 @@ replace_config_value () {
 		sed -i "s|^[ \t#]${1}=|${1}=|" ${DEFAULT_FILE}
 
 	grep -Eq "^[ \t]*${1}=" ${DEFAULT_FILE} || \
-		echo "${1}=" >${DEFAULT_FILE}
+		echo "${1}=" >>${DEFAULT_FILE}
 
 	sed -i "s|^[ \t]*${1}=.*|${1}=${2}|" ${DEFAULT_FILE}
 }
@@ -72,9 +72,9 @@ configure)
 
 	db_get miniupnpd/ip6script
 	if [ "${RET}" = "true" ] ; then
-		replace_config_value iniUPnPd_ip6tables_enable "yes"
+		replace_config_value MiniUPnPd_ip6tables_enable "yes"
 	else
-		replace_config_value iniUPnPd_ip6tables_enable "no"
+		replace_config_value MiniUPnPd_ip6tables_enable "no"
 	fi
 
 	db_stop