diff --git a/edit_aitext_form.php b/edit_aitext_form.php
index 989776c..705f5d4 100755
--- a/edit_aitext_form.php
+++ b/edit_aitext_form.php
@@ -51,6 +51,7 @@ protected function definition_inner($mform) {
         $mform->setType('aiprompt', PARAM_RAW);
         $mform->setDefault('aiprompt', get_config('qtype_aitext', 'defaultprompt'));
         $mform->addHelpButton('aiprompt', 'aiprompt', 'qtype_aitext');
+        $mform->addRule('aiprompt', get_string('aipromptmissing', 'qtype_aitext'), 'required');
 
         $mform->addElement('textarea', 'markscheme', get_string('markscheme', 'qtype_aitext'),
              ['maxlen' => 50, 'rows' => 6, 'size' => 30]);
diff --git a/lang/en/qtype_aitext.php b/lang/en/qtype_aitext.php
index 377d96a..dd1466c 100755
--- a/lang/en/qtype_aitext.php
+++ b/lang/en/qtype_aitext.php
@@ -27,6 +27,7 @@
 
 $string['aiprompt'] = 'AI Prompt';
 $string['aiprompt_help'] = 'A prompt for the Ai Grader. This is the guideline that AI uses to give feedback on the student response.';
+$string['aipromptmissing'] = 'The ai prompt is missing. Please enter a prompt on the basis of which the feedback is generated.';
 $string['answerfiles'] = 'Answer files';
 $string['answertext'] = 'Answer text';
 $string['attachmentsoptional'] = 'Attachments are optional';