diff --git a/htdocs/core/login/functions_http.php b/htdocs/core/login/functions_http.php
index c40e3b1609d..8aea6d40a2c 100644
--- a/htdocs/core/login/functions_http.php
+++ b/htdocs/core/login/functions_http.php
@@ -33,7 +33,7 @@
 */
 function check_user_password_http($usertotest,$passwordtotest,$entitytotest)
 {
-	dol_syslog("functions_http::check_user_password_http _SERVER[REMOTE_USER]=".$_SERVER["REMOTE_USER"]);
+	dol_syslog("functions_http::check_user_password_http _SERVER[REMOTE_USER]=".(empty($_SERVER["REMOTE_USER"])?'':$_SERVER["REMOTE_USER"]));
 
 	$login='';
 	if (! empty($_SERVER["REMOTE_USER"]))