diff --git a/lib/Validate/ISPN.php b/lib/Validate/ISPN.php
index 78c9c3dcf67fd18d5f259c4dc209d07b9a03ff64..e9b8a7835c1620b91e0d1635d49ff8120bd0c077 100644
--- a/lib/Validate/ISPN.php
+++ b/lib/Validate/ISPN.php
@@ -58,7 +58,7 @@
  */
 class Validate_ISPN
 {
-    function isbn($isbn)
+    public static function isbn($isbn)
     {
         if (preg_match("/[^0-9 IXSBN-]/", $isbn)) {
             return false;
@@ -91,7 +91,7 @@ class Validate_ISPN
      * @author Helgi Şormar <dufuz@php.net>
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function isbn13($isbn)
+    public static function isbn13($isbn)
     {
         if (preg_match("/[^0-9 ISBN-]/", $isbn)) {
             return false;
@@ -121,7 +121,7 @@ class Validate_ISPN
      * @author Damien Seguy <dams@nexen.net>
      * @author Helgi Şormar <dufuz@php.net>
      */
-    function isbn10($isbn)
+    public static function isbn10($isbn)
     {
         static  $weights_isbn = array(10,9,8,7,6,5,4,3,2);
 
@@ -157,7 +157,7 @@ class Validate_ISPN
      * @access public
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function issn($issn)
+    public static function issn($issn)
     {
         static $weights_issn = array(8,7,6,5,4,3,2);
 
@@ -191,7 +191,7 @@ class Validate_ISPN
      * @access public
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function ismn($ismn)
+    public static function ismn($ismn)
     {
         static $weights_ismn = array(3,1,3,1,3,1,3,1,3);
 
@@ -228,7 +228,7 @@ class Validate_ISPN
      * @access public
      * @author David Grant <david@grant.org.uk>
      */
-    function isrc($isrc)
+    public static function isrc($isrc)
     {
         $isrc = str_replace(array('ISRC', '-', ' '), '', strtoupper($isrc));
         if (!preg_match("/[A-Z]{2}[A-Z0-9]{3}[0-9]{7}/", $isrc)) {
@@ -252,7 +252,7 @@ class Validate_ISPN
      * @see Validate_ISPN::process()
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function ean8($ean)
+    public static function ean8($ean)
     {
         static $weights_ean8 = array(3,1,3,1,3,1,3);
         return Validate_ISPN::process($ean, 8, $weights_ean8, 10, 10);
@@ -272,7 +272,7 @@ class Validate_ISPN
      * @see Validate_ISPN::process()
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function ean13($ean)
+    public static function ean13($ean)
     {
         static $weights_ean13 = array(1,3,1,3,1,3,1,3,1,3,1,3);
         return Validate_ISPN::process($ean, 13, $weights_ean13, 10, 10);
@@ -292,7 +292,7 @@ class Validate_ISPN
      * @see Validate_ISPN::process()
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function ean14($ean)
+    public static function ean14($ean)
     {
         static $weights_ean14 = array(3,1,3,1,3,1,3,1,3,1,3,1,3);
         return Validate_ISPN::process($ean, 14, $weights_ean14, 10, 10);
@@ -312,7 +312,7 @@ class Validate_ISPN
      * @see Validate_ISPN::process()
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function ucc12($ucc)
+    public static function ucc12($ucc)
     {
         static $weights_ucc12 = array(3,1,3,1,3,1,3,1,3,1,3);
         return Validate_ISPN::process($ucc, 12, $weights_ucc12, 10, 10);
@@ -332,7 +332,7 @@ class Validate_ISPN
      * @see Validate_ISPN::process()
      * @author Piotr Klaban <makler@man.torun.pl>
      */
-    function sscc($sscc)
+    public static function sscc($sscc)
     {
         static $weights_sscc = array(3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3);
         return Validate_ISPN::process($sscc, 18, $weights_sscc, 10, 10);
@@ -351,7 +351,7 @@ class Validate_ISPN
      * @access public
      * @see Validate::_checkControlNumber()
      */
-    function process($data, $length, &$weights, $modulo = 10, $subtract = 0)
+    public static function process($data, $length, &$weights, $modulo = 10, $subtract = 0)
     {
         //$weights = array(3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3);
         //$weights = array_slice($weights, 0, $length);
diff --git a/lib/Validate/Validate.php b/lib/Validate/Validate.php
index 9be6806923e88ff19c9f4f3aa72d6177772df6f9..d382c398e9e3e7956123b6e5f37a9f8a25e2d354 100644
--- a/lib/Validate/Validate.php
+++ b/lib/Validate/Validate.php
@@ -583,7 +583,7 @@ class Validate
         return $ret;
     }
 
-    function _modf($val, $div) {
+    public static function _modf($val, $div) {
         if (function_exists('bcmod')) {
             return bcmod($val, $div);
         } elseif (function_exists('fmod')) {
@@ -604,7 +604,7 @@ class Validate
      *
      * @access protected
      */
-    function _multWeights($number, &$weights) {
+    public static function _multWeights($number, &$weights) {
         if (!is_array($weights)) {
             return -1;
         }
@@ -634,7 +634,7 @@ class Validate
      *
      * @access protected
      */
-    function _getControlNumber($number, &$weights, $modulo = 10, $subtract = 0, $allow_high = false) {
+    public static function _getControlNumber($number, &$weights, $modulo = 10, $subtract = 0, $allow_high = false) {
         // calc sum
         $sum = Validate::_multWeights($number, $weights);
         if ($sum == -1) {
@@ -663,7 +663,7 @@ class Validate
      *
      * @access protected
      */
-    function _checkControlNumber($number, &$weights, $modulo = 10, $subtract = 0) {
+    public static function _checkControlNumber($number, &$weights, $modulo = 10, $subtract = 0) {
         if (strlen($number) < count($weights)) {
             return false;
         }