diff --git a/inc/bans.php b/inc/bans.php
index 81e38006..e629ddae 100644
--- a/inc/bans.php
+++ b/inc/bans.php
@@ -1,8 +1,8 @@
 <?php
 
-require 'inc/lib/IP/Lifo/IP/IP.php';
-require 'inc/lib/IP/Lifo/IP/BC.php';
-require 'inc/lib/IP/Lifo/IP/CIDR.php';
+require_once 'inc/lib/IP/Lifo/IP/IP.php';
+require_once 'inc/lib/IP/Lifo/IP/BC.php';
+require_once 'inc/lib/IP/Lifo/IP/CIDR.php';
 
 use Lifo\IP\CIDR;
 
diff --git a/inc/functions.php b/inc/functions.php
index c2a7dc36..821cb03e 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -23,10 +23,13 @@ require_once 'inc/mod/auth.php';
 require_once 'inc/lock.php';
 require_once 'inc/queue.php';
 require_once 'inc/polyfill.php';
+require_once 'inc/lib/IP/Lifo/IP/IP.php';
 @include_once 'inc/lib/parsedown/Parsedown.php'; // fail silently, this isn't a critical piece of code
 
 require_once 'inc/anti-bot.php'; // DELETE ME THIS IS FOR print_err function only!
 
+use Lifo\IP\IP; // for expanding IPv6 address in DNSBL()
+
 if (!extension_loaded('gettext')) {
 	require_once 'inc/lib/gettext/gettext.inc';
 }
@@ -1807,23 +1810,7 @@ function ReverseIPv4Octets($ip) {
 }
 
 function ReverseIPv6Octets($ip) {
-	return strrev(implode(".", str_split(str_replace(':', '', inet_expand($ip)))));
-}
-
-// copypastad from lib/IP/Lifo/IP.php, TODO replace this with a proper include
-function inet_expand($ip)
-{
-	// strip possible cidr notation off
-	if (($pos = strpos($ip, '/')) !== false) {
-		$ip = substr($ip, 0, $pos);
-	}
-	$bytes = unpack('n*', inet_pton($ip));
-	if (count($bytes) > 2) {
-		return implode(':', array_map(function ($b) {
-			return sprintf("%04x", $b);
-		}, $bytes));
-	}
-	return $ip;
+	return strrev(implode(".", str_split(str_replace(':', '', IP::inet_expand($ip)))));
 }
 
 function wordfilters(&$body) {