diff --git a/htdocs/theme/eldy/manifest.json.php b/htdocs/theme/eldy/manifest.json.php
index 875d1981603..098ceb4aaae 100644
--- a/htdocs/theme/eldy/manifest.json.php
+++ b/htdocs/theme/eldy/manifest.json.php
@@ -34,14 +34,21 @@ if (!defined('NOLOGIN'))         define('NOLOGIN', '1');
 if (!defined('NOREQUIREMENU'))   define('NOREQUIREMENU', '1');
 if (!defined('NOREQUIREHTML'))   define('NOREQUIREHTML', '1');
 if (!defined('NOREQUIREAJAX'))   define('NOREQUIREAJAX', '1');
+if (!defined('NOSESSION'))       define('NOSESSION', '1');
 
 require_once __DIR__.'/../../main.inc.php';
 
 
 top_httphead('text/json');
 // Important: Following code is to avoid page request by browser and PHP CPU at each Dolibarr page access.
-if (empty($dolibarr_nocache)) header('Cache-Control: max-age=10800, public, must-revalidate');
-else header('Cache-Control: no-cache');
+if (empty($dolibarr_nocache)) {
+	header('Cache-Control: max-age=10800, public, must-revalidate');
+	// For a text/json, we must set an Expires to avoid to have it forced to an expired value by the web server
+	header('Expires: '.gmdate('D, d M Y H:i:s', dol_now('gmt') + 10800) . ' GMT');
+}
+else {
+	header('Cache-Control: no-cache');
+}
 
 
 $manifest = new stdClass();
diff --git a/htdocs/theme/md/manifest.json.php b/htdocs/theme/md/manifest.json.php
index 5f07177ed96..6051ff260ef 100644
--- a/htdocs/theme/md/manifest.json.php
+++ b/htdocs/theme/md/manifest.json.php
@@ -35,6 +35,7 @@ if (!defined('NOLOGIN'))         define('NOLOGIN', '1');
 if (!defined('NOREQUIREMENU'))   define('NOREQUIREMENU', '1');
 if (!defined('NOREQUIREHTML'))   define('NOREQUIREHTML', '1');
 if (!defined('NOREQUIREAJAX'))   define('NOREQUIREAJAX', '1');
+if (!defined('NOSESSION'))       define('NOSESSION', '1');
 
 require_once __DIR__.'/../../main.inc.php';
 
@@ -43,8 +44,14 @@ if (!empty($conf->global->MAIN_APPLICATION_TITLE)) $appli = $conf->global->MAIN_
 
 top_httphead('text/json');
 // Important: Following code is to avoid page request by browser and PHP CPU at each Dolibarr page access.
-if (empty($dolibarr_nocache)) header('Cache-Control: max-age=10800, public, must-revalidate');
-else header('Cache-Control: no-cache');
+if (empty($dolibarr_nocache)) {
+	header('Cache-Control: max-age=10800, public, must-revalidate');
+	// For a text/json, we must set an Expires to avoid to have it forced to an expired value by the web server
+	header('Expires: '.gmdate('D, d M Y H:i:s', dol_now('gmt') + 10800) . ' GMT');
+}
+else {
+	header('Cache-Control: no-cache');
+}
 
 ?>
 {