diff --git a/question/type/numerical/tests/helper.php b/question/type/numerical/tests/helper.php
index fc22c672351..049d56bcc4e 100644
--- a/question/type/numerical/tests/helper.php
+++ b/question/type/numerical/tests/helper.php
@@ -185,8 +185,16 @@ class qtype_numerical_test_helper extends question_test_helper {
      */
     public function get_numerical_question_form_data_pi3tries() {
         $form = $this->get_numerical_question_form_data_pi();
-        $form->hint[0]['text'] = 'First hint';
-        $form->hint[1]['text'] = 'Second hint';
+        $form->hint = [
+            [
+                'text' => 'First hint',
+                'format' => FORMAT_HTML,
+            ],
+            [
+                'text' => 'Second hint',
+                'format' => FORMAT_HTML,
+            ],
+        ];
         return $form;
     }