diff --git a/EventListener/SessionBackup.php b/EventListener/SessionBackup.php
index dffc2be..bdd8524 100644
--- a/EventListener/SessionBackup.php
+++ b/EventListener/SessionBackup.php
@@ -25,7 +25,7 @@ public function onKernelRequest(GetResponseEvent $event)
     {
         $session = $event->getRequest()->getSession();
 
-        if (!$session->isStarted()) {
+        if ($session === null || !$session->isStarted()) {
             return;
         }