diff --git a/question/type/calculatedsimple/edit_calculatedsimple_form.php b/question/type/calculatedsimple/edit_calculatedsimple_form.php
index 5e2307f13f9..93496c5685f 100644
--- a/question/type/calculatedsimple/edit_calculatedsimple_form.php
+++ b/question/type/calculatedsimple/edit_calculatedsimple_form.php
@@ -547,6 +547,8 @@ class question_edit_calculatedsimple_form extends question_edit_form {
     }
 
     function set_data($question) {
+        global $QTYPES;
+
             $answer = $this->answer;
             $default_values = array();
             if (count($answer)) {