diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index cfbda7171f3..db5ecb0eef5 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -365,8 +365,9 @@ function require_login($courseid=0) {
             $SESSION->fromurl  = $_SERVER["HTTP_REFERER"];
         }
         $USER = NULL;
-        $loginguest = (isset($CFG->loginguests) and $CFG->autologinguests 
-            and $courseid and get_field('course','guest','id',$courseid)) ? '?loginguest=true' : '';
+        if (!empty($CFG->autologinguests)) {
+            $loginguest = ($courseid and get_field('course','guest','id',$courseid)) ? '?loginguest=true' : '';
+        }
         if (empty($CFG->loginhttps)) {
             redirect("$CFG->wwwroot/login/index.php$loginguest");
         } else {