diff --git a/htdocs/master.inc.php b/htdocs/master.inc.php
index 9e1c5ad2e14..b39d5216218 100644
--- a/htdocs/master.inc.php
+++ b/htdocs/master.inc.php
@@ -83,6 +83,7 @@ if (! empty($dolibarr_main_document_root_alt))
 			print "Should found something like following examples:<br>\n";
 			print "\"/extensions\"<br>\n";
 			print "\"/extensions1,/extensions2,...\"<br>\n";
+			print "\"/../extensions\"<br>\n";
 			print "\"/custom\"<br>\n";
 			exit;
 		}