diff --git a/classes/edit_form.php b/classes/edit_form.php
index 064ead5..d6c3d20 100644
--- a/classes/edit_form.php
+++ b/classes/edit_form.php
@@ -56,7 +56,6 @@ class edit_form extends \moodleform {
 
         $mform->addElement('textarea', 'html', get_string('html', 'htmlcert'));
         $mform->setType('html', PARAM_RAW);
-        $mform->addRule('html', null, 'required');
 
         // Add the submit buttons.
         $group = array();