diff --git a/enrol/ajax.php b/enrol/ajax.php
index ede3c5a377c..64dba6a06e0 100644
--- a/enrol/ajax.php
+++ b/enrol/ajax.php
@@ -54,9 +54,9 @@ echo $OUTPUT->header(); // send headers
 
 $manager = new course_enrolment_manager($PAGE, $course);
 
-$outcome = new stdClass;
+$outcome = new stdClass();
 $outcome->success = true;
-$outcome->response = new stdClass;
+$outcome->response = new stdClass();
 $outcome->error = '';
 
 switch ($action) {
@@ -99,6 +99,10 @@ switch ($action) {
             $user->fullname = fullname($user);
             unset($user->id);
         }
+        // Chrome will display users in the order of the array keys, so we need
+        // to ensure that the results ordered array keys. Fortunately, the JavaScript
+        // does not care what the array keys are. It uses user.id where necessary.
+        $outcome->response['users'] = array_values($outcome->response['users']);
         $outcome->success = true;
         break;
     default:
diff --git a/enrol/manual/ajax.php b/enrol/manual/ajax.php
index faf8ac02025..492634f6c30 100644
--- a/enrol/manual/ajax.php
+++ b/enrol/manual/ajax.php
@@ -51,9 +51,9 @@ echo $OUTPUT->header(); // Send headers.
 
 $manager = new course_enrolment_manager($PAGE, $course);
 
-$outcome = new stdClass;
+$outcome = new stdClass();
 $outcome->success = true;
-$outcome->response = new stdClass;
+$outcome->response = new stdClass();
 $outcome->error = '';
 
 switch ($action) {
@@ -77,6 +77,10 @@ switch ($action) {
             }
             $user->extrafields = implode(', ', $fieldvalues);
         }
+        // Chrome will display users in the order of the array keys, so we need
+        // to ensure that the results ordered array keys. Fortunately, the JavaScript
+        // does not care what the array keys are. It uses user.id where necessary.
+        $outcome->response['users'] = array_values($outcome->response['users']);
         $outcome->success = true;
         break;
     case 'enrol':