diff --git a/mod/quiz/renderer.php b/mod/quiz/renderer.php
index bedfad83b92..363159661f1 100644
--- a/mod/quiz/renderer.php
+++ b/mod/quiz/renderer.php
@@ -349,7 +349,7 @@ class mod_quiz_renderer extends plugin_renderer_base {
      * @return string HTML fragment.
      */
     protected function render_quiz_nav_question_button(quiz_nav_question_button $button) {
-        $classes = array('qnbutton', $button->stateclass, $button->navmethod, 'btn', 'btn-secondary');
+        $classes = array('qnbutton', $button->stateclass, $button->navmethod, 'btn');
         $extrainfo = array();
 
         if ($button->currentpage) {