diff --git a/htdocs/core/conf.class.php b/htdocs/core/conf.class.php
index 749c49a1134..9f0cf91eb7d 100644
--- a/htdocs/core/conf.class.php
+++ b/htdocs/core/conf.class.php
@@ -334,7 +334,7 @@ class Conf
 		// $this->theme et $this->css
 		if (empty($this->global->MAIN_THEME)) $this->global->MAIN_THEME="eldy";
 		$this->theme=$this->global->MAIN_THEME;
-		$this->css  = "/theme/".$this->theme."/".$this->theme.".css";
+		$this->css  = "/theme/".$this->theme."/".$this->theme.".css.php";
 
 		// $this->email_from = email pour envoi par dolibarr des mails automatiques
 		$this->email_from = "dolibarr-robot@domain.com";