diff --git a/mod/quiz/classes/external.php b/mod/quiz/classes/external.php
index d1d82b545ad..73a48ac27b0 100644
--- a/mod/quiz/classes/external.php
+++ b/mod/quiz/classes/external.php
@@ -495,7 +495,8 @@ class mod_quiz_external extends external_api {
      * @since Moodle 3.1
      */
     public static function get_user_best_grade($quizid, $userid = 0) {
-        global $DB, $USER;
+        global $DB, $USER, $CFG;
+        require_once($CFG->libdir . '/gradelib.php');
 
         $warnings = array();
 
@@ -545,6 +546,17 @@ class mod_quiz_external extends external_api {
             $result['hasgrade'] = true;
             $result['grade'] = $grade;
         }
+
+        // Inform user of the grade to pass if non-zero.
+        $gradinginfo = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $user->id);
+        if (!empty($gradinginfo->items)) {
+            $item = $gradinginfo->items[0];
+
+            if ($item && grade_floats_different($item->gradepass, 0)) {
+                $result['gradetopass'] = $item->gradepass;
+            }
+        }
+
         $result['warnings'] = $warnings;
         return $result;
     }
@@ -560,6 +572,7 @@ class mod_quiz_external extends external_api {
             array(
                 'hasgrade' => new external_value(PARAM_BOOL, 'Whether the user has a grade on the given quiz.'),
                 'grade' => new external_value(PARAM_FLOAT, 'The grade (only if the user has a grade).', VALUE_OPTIONAL),
+                'gradetopass' => new external_value(PARAM_FLOAT, 'The grade to pass the quiz (only if set).', VALUE_OPTIONAL),
                 'warnings' => new external_warnings(),
             )
         );
diff --git a/mod/quiz/tests/external_test.php b/mod/quiz/tests/external_test.php
index 12084f033c7..8640f9e959b 100644
--- a/mod/quiz/tests/external_test.php
+++ b/mod/quiz/tests/external_test.php
@@ -552,6 +552,7 @@ class mod_quiz_external_testcase extends externallib_advanced_testcase {
         // Now I have grades.
         $this->assertTrue($result['hasgrade']);
         $this->assertEquals(100.0, $result['grade']);
+        $this->assertEquals(80, $result['gradetopass']);
 
         // We should not see other users grades.
         $anotherstudent = self::getDataGenerator()->create_user();
@@ -572,6 +573,7 @@ class mod_quiz_external_testcase extends externallib_advanced_testcase {
 
         $this->assertTrue($result['hasgrade']);
         $this->assertEquals(100.0, $result['grade']);
+        $this->assertEquals(80, $result['gradetopass']);
 
         // Invalid user.
         try {
diff --git a/mod/quiz/upgrade.txt b/mod/quiz/upgrade.txt
index 3af165d4297..8fb4e3d22d4 100644
--- a/mod/quiz/upgrade.txt
+++ b/mod/quiz/upgrade.txt
@@ -1,5 +1,10 @@
 This files describes API changes in the quiz code.
 
+=== 3.11 ===
+
+* External function mod_quiz_external::get_user_best_grade now returns and additional optional field:
+  - gradetopass: The grade to pass the quiz (if set)
+
 === 3.10.1 ===
 
 * External functions mod_quiz_external::get_attempt_data, mod_quiz_external::get_attempt_summary