diff --git a/htdocs/core/lib/security.lib.php b/htdocs/core/lib/security.lib.php
index dc739220c07..483567aa3d0 100644
--- a/htdocs/core/lib/security.lib.php
+++ b/htdocs/core/lib/security.lib.php
@@ -122,7 +122,7 @@ function dol_hash($chain, $type = '0')
 	}
 
 	// Salt value
-	if (! empty($conf->global->MAIN_SECURITY_SALT) && ( ! $type == '4' || ! $type == 'md5openldap')) $chain=$conf->global->MAIN_SECURITY_SALT.$chain;
+	if (! empty($conf->global->MAIN_SECURITY_SALT) && ($type !== '4' || $type !== 'md5openldap')) $chain = $conf->global->MAIN_SECURITY_SALT.$chain;
 
 	if ($type == '1' || $type == 'sha1') return sha1($chain);
 	elseif ($type == '2' || $type == 'sha1md5') return sha1(md5($chain));