diff --git a/mod/quiz/config.html b/mod/quiz/config.html
index 375ae3304fc..2ee518b1139 100644
--- a/mod/quiz/config.html
+++ b/mod/quiz/config.html
@@ -215,7 +215,7 @@
   <td align="right"><b><?php print_string("adaptive", "quiz") ?>:</b></td>
   <td>
     <?php
-        choose_from_menu($yesnooptions, "adaptive", $CFG->quiz_optionflags & QUIZ_ADAPTIVE, "");
+        choose_from_menu($yesnooptions, "adaptive", ($CFG->quiz_optionflags & QUIZ_ADAPTIVE) ? 1 : 0, "");
         helpbutton("adaptive", get_string("adaptive","quiz"), "quiz");
     ?>
   </td>
diff --git a/mod/quiz/defaults.php b/mod/quiz/defaults.php
index 92670047842..d0818df5b01 100644
--- a/mod/quiz/defaults.php
+++ b/mod/quiz/defaults.php
@@ -19,7 +19,7 @@
        'quiz_timelimit' => 0,
        'quiz_optionflags' => 1,
        'quiz_penaltyscheme' => 1,
-       'quiz_adaptive' => 1,
+       'quiz_adaptive' => QUIZ_ADAPTIVE,
 
        'quiz_fix_review' => 0,
        'quiz_fix_attemptonlast' => 0,
diff --git a/mod/quiz/lib.php b/mod/quiz/lib.php
index a97c2ab5ff8..8471cb0f779 100644
--- a/mod/quiz/lib.php
+++ b/mod/quiz/lib.php
@@ -680,7 +680,7 @@ function quiz_process_options(&$form) {
     $review = 0;
 
     if (!empty($form->adaptive)) {
-        $optionflags += QUIZ_ADAPTIVE;
+        $optionflags |= QUIZ_ADAPTIVE;
     }
 
     if (isset($form->responsesimmediately)) {
diff --git a/mod/quiz/mod.html b/mod/quiz/mod.html
index c6e3003325d..22de6e3b4a6 100644
--- a/mod/quiz/mod.html
+++ b/mod/quiz/mod.html
@@ -260,7 +260,7 @@
         <td align="right"><b><?php print_string("adaptive", "quiz") ?>:</b></td>
          <td align="left">
         <?php
-            choose_from_menu($yesnooptions, "adaptive", $form->optionflags & QUIZ_ADAPTIVE, "");
+            choose_from_menu($yesnooptions, "adaptive", ($form->optionflags & QUIZ_ADAPTIVE) ? 1 : 0, "");
             helpbutton("adaptive", get_string("adaptive","quiz"), "quiz");
          ?>
         </td>
@@ -488,7 +488,7 @@
         <td align="right"><b><?php print_string("adaptive", "quiz") ?>:</b></td>
          <td align="left">
         <?php
-            choose_from_menu($yesnooptions, "adaptive", $form->optionflags & QUIZ_ADAPTIVE, "");
+            choose_from_menu($yesnooptions, "adaptive", ($form->optionflags & QUIZ_ADAPTIVE) ? 1 : 0, "");
             helpbutton("adaptive", get_string("adaptive","quiz"), "quiz");
          ?>
         </td>