diff --git a/include/auth.php b/include/auth.php
index 2258128c5d..d819a636b0 100644
--- a/include/auth.php
+++ b/include/auth.php
@@ -1,4 +1,7 @@
 <?php
+
+use \Friendica\Core\Config;
+
 require_once('include/security.php');
 require_once('include/datetime.php');
 
@@ -21,7 +24,7 @@ if (isset($_COOKIE["Friendica"])) {
 			// Renew the cookie
 			// Expires after 7 days by default,
 			// can be set via system.auth_cookie_lifetime
-			$authcookiedays = get_config('system','auth_cookie_lifetime') || 7;
+			$authcookiedays = Config::get('system', 'auth_cookie_lifetime') || 7;
 			new_cookie($authcookiedays*24*60*60, $r[0]);
 
 			// Do the authentification if not done by now