diff --git a/mod/glossary/exportfile.php b/mod/glossary/exportfile.php
index f2d10471813..aeebd036f15 100644
--- a/mod/glossary/exportfile.php
+++ b/mod/glossary/exportfile.php
@@ -4,6 +4,7 @@
 define('NO_DEBUG_DISPLAY', true);
 
 require_once("../../config.php");
+require_once("$CFG->libdir/filelib.php");
 require_once("lib.php");
 
 $id = required_param('id', PARAM_INT);      // Course Module ID