diff --git a/htdocs/theme/auguria/auguria.css.php b/htdocs/theme/auguria/auguria.css.php
index 3e42e251747..3ca25cfc951 100644
--- a/htdocs/theme/auguria/auguria.css.php
+++ b/htdocs/theme/auguria/auguria.css.php
@@ -31,7 +31,7 @@ require("../../conf/conf.php");
 header('Content-type: text/css');
 // Important: Avoid page request by browser and dynamic build at
 // each Dolibarr page access.
-if (! $conf->global->MAIN_FEATURES_LEVEL)
+if (! isset($conf->global->MAIN_FEATURES_LEVEL) || $conf->global->MAIN_FEATURES_LEVEL < 2)
 {
 	//header('Cache-Control: max-age=3600, public, must-revalidate');
 }
diff --git a/htdocs/theme/eldy/eldy.css.php b/htdocs/theme/eldy/eldy.css.php
index 075997fbe31..7389ffd23ad 100644
--- a/htdocs/theme/eldy/eldy.css.php
+++ b/htdocs/theme/eldy/eldy.css.php
@@ -33,7 +33,7 @@ require("../../conf/conf.php");
 header('Content-type: text/css');
 // Important: Avoid page request by browser and dynamic build at
 // each Dolibarr page access.
-if (! $conf->global->MAIN_FEATURES_LEVEL)
+if (! isset($conf->global->MAIN_FEATURES_LEVEL) || $conf->global->MAIN_FEATURES_LEVEL < 2)
 {
 	header('Cache-Control: max-age=3600, public, must-revalidate');
 }
diff --git a/htdocs/theme/freelug/freelug.css.php b/htdocs/theme/freelug/freelug.css.php
index 9accb1ed7e7..7852e4a0837 100644
--- a/htdocs/theme/freelug/freelug.css.php
+++ b/htdocs/theme/freelug/freelug.css.php
@@ -32,7 +32,7 @@ require("../../conf/conf.php");
 header('Content-type: text/css');
 // Important: Avoid page request by browser and dynamic build at
 // each Dolibarr page access.
-if (! $conf->global->MAIN_FEATURES_LEVEL)
+if (! isset($conf->global->MAIN_FEATURES_LEVEL) || $conf->global->MAIN_FEATURES_LEVEL < 2)
 {
 	header('Cache-Control: max-age=3600, public, must-revalidate');
 }
diff --git a/htdocs/theme/yellow/yellow.css.php b/htdocs/theme/yellow/yellow.css.php
index 026b7f54c01..aaad1257707 100644
--- a/htdocs/theme/yellow/yellow.css.php
+++ b/htdocs/theme/yellow/yellow.css.php
@@ -32,7 +32,7 @@ require("../../conf/conf.php");
 header('Content-type: text/css');
 // Important: Avoid page request by browser and dynamic build at
 // each Dolibarr page access.
-if (! $conf->global->MAIN_FEATURES_LEVEL)
+if (! isset($conf->global->MAIN_FEATURES_LEVEL) || $conf->global->MAIN_FEATURES_LEVEL < 2)
 {
 	header('Cache-Control: max-age=3600, public, must-revalidate');
 }