diff --git a/lib/htmlpurifier/HTMLPurifier/AttrDef/Lang.php b/lib/htmlpurifier/HTMLPurifier/AttrDef/Lang.php
index 4fbd9f67a28..e9cdda7adf9 100644
--- a/lib/htmlpurifier/HTMLPurifier/AttrDef/Lang.php
+++ b/lib/htmlpurifier/HTMLPurifier/AttrDef/Lang.php
@@ -10,6 +10,10 @@ class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
 {
     
     function validate($string, $config, &$context) {
+
+// moodle change - we use special lang strings unfortunatelly
+        return ereg_replace('[^0-9a-zA-Z_-]', '', $string);
+// moodle change end
         
         $string = trim($string);
         if (!$string) return false;
diff --git a/lib/htmlpurifier/HTMLPurifier/HTMLModule/XMLCommonAttributes.php b/lib/htmlpurifier/HTMLPurifier/HTMLModule/XMLCommonAttributes.php
index 67f7fc8ae16..e8a8424d50b 100644
--- a/lib/htmlpurifier/HTMLPurifier/HTMLModule/XMLCommonAttributes.php
+++ b/lib/htmlpurifier/HTMLPurifier/HTMLModule/XMLCommonAttributes.php
@@ -7,9 +7,11 @@ class HTMLPurifier_HTMLModule_XMLCommonAttributes extends HTMLPurifier_HTMLModul
     var $name = 'XMLCommonAttributes';
     
     var $attr_collections = array(
+/* moodle comment - xml:lang breaks our multilang
         'Lang' => array(
             'xml:lang' => 'LanguageCode',
         )
+*/
     );
 }
 
diff --git a/lib/htmlpurifier/readme_moodle.txt b/lib/htmlpurifier/readme_moodle.txt
index f1c12eb84ac..c3c426aef2a 100644
--- a/lib/htmlpurifier/readme_moodle.txt
+++ b/lib/htmlpurifier/readme_moodle.txt
@@ -1,7 +1,9 @@
-Description of HTML Purifier v2.1.1 Lite library import into Moodle
+Description of HTML Purifier v2.1.2 Lite library import into Moodle
 
 Changes:
- * Text.php - added nolink, tex, lang and algebra tags
+ * HMLTModule/Text.php - added  <nolink>, <tex>, <lang> and <algebra> tags
+ * HMLTModule/XMLCommonAttributes.php - remove xml:lang - needed for multilang
+ * AttrDef/Lang.php - relaxt lang check - needed for multilang
 
 skodak