diff --git a/libraries/config/ConfigFile.php b/libraries/config/ConfigFile.php
index 093d84ef48..68683f4f23 100644
--- a/libraries/config/ConfigFile.php
+++ b/libraries/config/ConfigFile.php
@@ -543,7 +543,7 @@ class ConfigFile
      *
      * @return string
      */
-    public function getDefaultTempDirectory()
+    public static function getDefaultTempDirectory()
     {
         $tmp_subdir = null;
         if (! empty($GLOBALS['cfg']['TempDir']) && @is_writable($GLOBALS['cfg']['TempDir'])) {