diff --git a/mod/quiz/lib.php b/mod/quiz/lib.php
index 9ece885fcf8..5e0949d6015 100644
--- a/mod/quiz/lib.php
+++ b/mod/quiz/lib.php
@@ -1128,6 +1128,14 @@ function quiz_process_options($quiz) {
     $quiz->reviewoverallfeedback = quiz_review_option_form_to_db($quiz, 'overallfeedback');
     $quiz->reviewattempt |= mod_quiz_display_options::DURING;
     $quiz->reviewoverallfeedback &= ~mod_quiz_display_options::DURING;
+
+    // Ensure that disabled checkboxes in completion settings are set to 0.
+    if (empty($quiz->completionusegrade)) {
+        $quiz->completionpass = 0;
+    }
+    if (empty($quiz->completionpass)) {
+        $quiz->completionattemptsexhausted = 0;
+    }
 }
 
 /**
diff --git a/mod/quiz/mod_form.php b/mod/quiz/mod_form.php
index fda0558604c..e372bc2852c 100644
--- a/mod/quiz/mod_form.php
+++ b/mod/quiz/mod_form.php
@@ -517,11 +517,6 @@ class mod_quiz_mod_form extends moodleform_mod {
                 $toform[$name] = $value;
             }
         }
-
-        // Completion settings check.
-        if (empty($toform['completionusegrade'])) {
-            $toform['completionpass'] = 0; // Forced unchecked.
-        }
     }
 
     public function validation($data, $files) {