diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 00a8ea821e2..f1de8ba630e 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -3850,7 +3850,7 @@ function dol_print_error($db = '', $error = '', $errors = null)
 		{
 			$out .= "<b>".$langs->trans("OS").":</b> ".php_uname()."<br>\n";
 		}
-		$out .= "<b>".$langs->trans("UserAgent").":</b> ".$_SERVER["HTTP_USER_AGENT"]."<br>\n";
+		$out .= "<b>".$langs->trans("UserAgent").":</b> ".dol_htmlentities($_SERVER["HTTP_USER_AGENT"], ENT_COMPAT, 'UTF-8')."<br>\n";
 		$out .= "<br>\n";
 		$out .= "<b>".$langs->trans("RequestedUrl").":</b> ".dol_htmlentities($_SERVER["REQUEST_URI"], ENT_COMPAT, 'UTF-8')."<br>\n";
 		$out .= "<b>".$langs->trans("Referer").":</b> ".(isset($_SERVER["HTTP_REFERER"]) ?dol_htmlentities($_SERVER["HTTP_REFERER"], ENT_COMPAT, 'UTF-8') : '')."<br>\n";