diff --git a/backup/util/helper/backup_cron_helper.class.php b/backup/util/helper/backup_cron_helper.class.php
index b6d81abde7f..8a3b19d103a 100644
--- a/backup/util/helper/backup_cron_helper.class.php
+++ b/backup/util/helper/backup_cron_helper.class.php
@@ -530,18 +530,7 @@ abstract class backup_cron_automated_helper {
         if (!empty($dir) && ($storage == 1 || $storage == 2)) {
             // Calculate backup filename regex, ignoring the date/time/info parts that can be
             // variable, depending of languages, formats and automated backup settings
-
-
-            // MDL-33531: use different filenames depending on backup_shortname option
-            if ( !empty($config->backup_shortname) ) {
-                $context = get_context_instance(CONTEXT_COURSE, $course->id);
-                $courseref = format_string($course->shortname, true, array('context' => $context));
-                $courseref = str_replace(' ', '_', $courseref);
-                $courseref = textlib::strtolower(trim(clean_filename($courseref), '_'));
-            } else {
-                $courseref = $course->id;
-            }
-            $filename = $backupword . '-' . backup::FORMAT_MOODLE . '-' . backup::TYPE_1COURSE . '-' .$courseref . '-';
+            $filename = $backupword . '-' . backup::FORMAT_MOODLE . '-' . backup::TYPE_1COURSE . '-' .$course->id . '-';
             $regex = '#^'.preg_quote($filename, '#').'.*\.mbz$#';
 
             // Store all the matching files into fullpath => timemodified array