diff --git a/lib/SimpleSAML/SessionHandlerPHP.php b/lib/SimpleSAML/SessionHandlerPHP.php
index 3686356ac04aad906f5b2edf36e2414a157550b2..1e9d7850e7d252dff3eb551bffcf67738cbe24fb 100644
--- a/lib/SimpleSAML/SessionHandlerPHP.php
+++ b/lib/SimpleSAML/SessionHandlerPHP.php
@@ -251,7 +251,7 @@ class SessionHandlerPHP extends SessionHandler
                 throw new \SimpleSAML\Error\Exception('Cannot load PHP session with a specific ID.');
             }
         } elseif (session_id() === '') {
-            self::getCookieSessionId();
+            $this->getCookieSessionId();
         }
 
         if (!isset($_SESSION['SimpleSAMLphp_SESSION'])) {