diff --git a/main/inc/lib/api.lib.php b/main/inc/lib/api.lib.php
index 1268c44445..6af3a95482 100644
--- a/main/inc/lib/api.lib.php
+++ b/main/inc/lib/api.lib.php
@@ -459,7 +459,7 @@ define('RESULT_DISABLE_SHOW_FINAL_SCORE_ONLY_WITH_CATEGORIES', 3); //Show final
 
 define('EXERCISE_MAX_NAME_SIZE', 80);
 
-// Question types
+// Question types (edit next array as well when adding values)
 // @todo move into a class
 define('UNIQUE_ANSWER', 1);
 define('MULTIPLE_ANSWER', 2);
@@ -481,6 +481,29 @@ define('UNIQUE_ANSWER_IMAGE', 17);
 define('DRAGGABLE', 18);
 define('MATCHING_DRAGGABLE', 19);
 
+// one big string with all question types, for the validator in pear/HTML/QuickForm/Rule/QuestionType
+define('QUESTION_TYPES',
+    UNIQUE_ANSWER.':'.
+    MULTIPLE_ANSWER.':'.
+    FILL_IN_BLANKS.':'.
+    MATCHING.':'.
+    FREE_ANSWER.':'.
+    HOT_SPOT.':'.
+    HOT_SPOT_ORDER.':'.
+    HOT_SPOT_DELINEATION.':'.
+    MULTIPLE_ANSWER_COMBINATION.':'.
+    UNIQUE_ANSWER_NO_OPTION.':'.
+    MULTIPLE_ANSWER_TRUE_FALSE.':'.
+    MULTIPLE_ANSWER_COMBINATION_TRUE_FALSE.':'.
+    ORAL_EXPRESSION.':'.
+    GLOBAL_MULTIPLE_ANSWER.':'.
+    MEDIA_QUESTION.':'.
+    CALCULATED_ANSWER.':'.
+    UNIQUE_ANSWER_IMAGE.':'.
+    DRAGGABLE.':'.
+    MATCHING_DRAGGABLE
+);
+
 //Some alias used in the QTI exports
 define('MCUA', 1);
 define('TF', 1);
diff --git a/main/inc/lib/pear/HTML/QuickForm/Rule/QuestionType.php b/main/inc/lib/pear/HTML/QuickForm/Rule/QuestionType.php
new file mode 100755
index 0000000000..df6f4fbf20
--- /dev/null
+++ b/main/inc/lib/pear/HTML/QuickForm/Rule/QuestionType.php
@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * Required elements validation
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: This source file is subject to version 3.01 of the PHP license
+ * that is available through the world-wide-web at the following URI:
+ * http://www.php.net/license/3_01.txt If you did not receive a copy of
+ * the PHP License and are unable to obtain it through the web, please
+ * send a note to license@php.net so we can mail you a copy immediately.
+ *
+ * @category    HTML
+ * @package     HTML_QuickForm
+ * @author      Bertrand Mansion <bmansion@mamasam.com>
+ * @copyright   2001-2009 The PHP Group
+ * @license     http://www.php.net/license/3_01.txt PHP License 3.01
+ * @version     CVS: $Id: Required.php,v 1.6 2009/04/04 21:34:04 avb Exp $
+ * @link        http://pear.php.net/package/HTML_QuickForm
+ */
+
+/**
+ * Required elements validation
+ *
+ * @category    HTML
+ * @package     HTML_QuickForm
+ * @author      Yannick Warnier <yannick.warnier@beeznest.com>
+ * @version     Based on release: 3.2.11
+ * @since       3.2
+ */
+class HTML_QuickForm_Rule_QuestionType extends HTML_QuickForm_Rule
+{
+    /**
+     * Checks if a value is one of the accepted question types
+     *
+     * @param     string    $value      Value to check
+     * @param     mixed     $options    Not used yet
+     * @access    public
+     * @return    boolean   true if value is not empty
+     */
+    public function validate($value, $options = null)
+    {
+        // It seems this is a file.
+        if (in_array($value, preg_split('/:/', QUESTION_TYPES))) {
+            return true;
+        }
+
+        return false;
+    }
+}
diff --git a/main/inc/lib/pear/HTML/QuickForm/RuleRegistry.php b/main/inc/lib/pear/HTML/QuickForm/RuleRegistry.php
index c56e355ddc..4b90f49830 100755
--- a/main/inc/lib/pear/HTML/QuickForm/RuleRegistry.php
+++ b/main/inc/lib/pear/HTML/QuickForm/RuleRegistry.php
@@ -94,7 +94,7 @@ class HTML_QuickForm_RuleRegistry
 
         } elseif ($type == 'function' || $type == 'callback') {
             // Callback function
-            $rule =& $this->getRule('callback');
+            $rule = $this->getRule('callback');
             $rule->addData($ruleName, $data1, $data2, 'function' == $type);
         } elseif (is_object($data1)) {
             // An instance of HTML_QuickForm_Rule
@@ -148,7 +148,9 @@ class HTML_QuickForm_RuleRegistry
             'uploadedfile' => 'HTML_QuickForm_Rule_UploadFile',
             'maxfilesize', 'HTML_QuickForm_Rule_MaxFileSize',
             'mimetype', 'HTML_QuickForm_Rule_MimeType',
-            'filename', 'HTML_QuickForm_Rule_FileName'
+            'filename', 'HTML_QuickForm_Rule_FileName',
+            'validquestiontype' => 'HTML_QuickForm_Rule_QuestionType',
+
         );
 
         $class = $rules[$ruleName];