diff --git a/htdocs/core/js/datepicker.js.php b/htdocs/core/js/datepicker.js.php
index ca5c0fba8f84097d96011eb5974b9ccbb99b945c..044fddcd0bafdc5ea26a3142905c44c41b67ef3f 100644
--- a/htdocs/core/js/datepicker.js.php
+++ b/htdocs/core/js/datepicker.js.php
@@ -38,6 +38,7 @@ require_once("../../main.inc.php");
 
 // Define javascript type
 header('Content-type: text/javascript');
+header("Content-type: text/html; charset=UTF-8");
 // Important: Following code is to avoid page request by browser and PHP CPU at each Dolibarr page access.
 if (empty($dolibarr_nocache)) header('Cache-Control: max-age=3600, public, must-revalidate');
 else header('Cache-Control: no-cache');