diff --git a/htdocs/core/lib/files.lib.php b/htdocs/core/lib/files.lib.php
index 50550e3feb6..708bb9d7987 100644
--- a/htdocs/core/lib/files.lib.php
+++ b/htdocs/core/lib/files.lib.php
@@ -1170,6 +1170,7 @@ function dol_delete_file($file, $disableglob = 0, $nophperrors = 0, $nohook = 0,
 
 	if (empty($nohook) && $reshook != 0) // reshook = 0 to do standard actions, 1 = ok and replace, -1 = ko
 	{
+		dol_syslog("reshook=".$reshook);
 		if ($reshook < 0) return false;
 		return true;
 	} else {