diff -up source/CAS/Client.php.php53 source/CAS/Client.php
--- source/CAS/Client.php.php53	2017-04-11 09:20:34.296013390 +0200
+++ source/CAS/Client.php	2017-04-11 09:21:01.735148734 +0200
@@ -1698,12 +1698,7 @@ class CAS_Client
         phpCAS::trace("Destroying session : ".session_id());
         session_unset();
         session_destroy();
-        if (session_status() === PHP_SESSION_NONE) {
-            phpCAS::trace("Session terminated");
-        } else {
-            phpCAS::error("Session was not terminated");
-            phpCAS::trace("Session was not terminated");
-        }
+        phpCAS::trace("Session terminated");
         $lang = $this->getLangObj();
         $this->printHTMLHeader($lang->getLogout());
         printf('<p>'.$lang->getShouldHaveBeenRedirected(). '</p>', $cas_url);