diff --git a/inc/common.php b/inc/common.php
index 1532c523a1ccd7c0295ccbeae25007ea9c746757..27b5663b9ada5a346b9e0a901c26a9593d0ce605 100644
--- a/inc/common.php
+++ b/inc/common.php
@@ -594,11 +594,31 @@ function clientIP($single=false){
   if(!empty($_SERVER['HTTP_X_REAL_IP']))
     $ip = array_merge($ip,explode(',',$_SERVER['HTTP_X_REAL_IP']));
 
+  // some IPv4/v6 regexps borrowed from Feyd
+  // see: http://forums.devnetwork.net/viewtopic.php?f=38&t=53479
+  $dec_octet = '(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|[0-9])';
+  $hex_digit = '[A-Fa-f0-9]';
+  $h16 = "{$hex_digit}{1,4}";
+  $IPv4Address = "$dec_octet\\.$dec_octet\\.$dec_octet\\.$dec_octet";
+  $ls32 = "(?:$h16:$h16|$IPv4Address)";
+  $IPv6Address =
+    "(?:(?:{$IPv4Address})|(?:".
+    "(?:$h16:){6}$ls32" .
+    "|::(?:$h16:){5}$ls32" .
+    "|(?:$h16)?::(?:$h16:){4}$ls32" .
+    "|(?:(?:$h16:){0,1}$h16)?::(?:$h16:){3}$ls32" .
+    "|(?:(?:$h16:){0,2}$h16)?::(?:$h16:){2}$ls32" .
+    "|(?:(?:$h16:){0,3}$h16)?::(?:$h16:){1}$ls32" .
+    "|(?:(?:$h16:){0,4}$h16)?::$ls32" .
+    "|(?:(?:$h16:){0,5}$h16)?::$h16" .
+    "|(?:(?:$h16:){0,6}$h16)?::" .
+    ")(?:\\/(?:12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))?)";
+
   // remove any non-IP stuff
   $cnt = count($ip);
   $match = array();
   for($i=0; $i<$cnt; $i++){
-    if(preg_match('/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/',$ip[$i],$match)) {
+    if(preg_match("/^$IPv4Address$/",$ip[$i],$match) || preg_match("/^$IPv6Address$/",$ip[$i],$match)) {
       $ip[$i] = $match[0];
     } else {
       $ip[$i] = '';