diff --git a/htdocs/core/lib/files.lib.php b/htdocs/core/lib/files.lib.php
index d357141fa4d..577d6356752 100644
--- a/htdocs/core/lib/files.lib.php
+++ b/htdocs/core/lib/files.lib.php
@@ -159,7 +159,7 @@ function dol_dir_list($path, $types="all", $recursive=0, $filter="", $excludefil
 						// if we're in a directory and we want recursive behavior, call this function again
 						if ($recursive)
 						{
-							$file_list = array_merge($file_list, dol_dir_list($path."/".$file, $types, $recursive, $filter, $excludefilter, $sortcriteria, $sortorder, $mode, $nohook, ($relativename?$relativename.'/':'').$file));
+							$file_list = array_merge($file_list, dol_dir_list($path."/".$file, $types, $recursive, $filter, $excludefilter, $sortcriteria, $sortorder, $mode, $nohook, ($relativename!=''?$relativename.'/':'').$file));
 						}
 					}
 					else if (! $isdir && (($types == "files") || ($types == "all")))