diff --git a/lib/SimpleSAML/Session.php b/lib/SimpleSAML/Session.php
index 71326dd8da06b90bee351f561bf07a54b3a2201c..a8ef4b26dc353bd2c09d066e736b5f6959c4c221 100644
--- a/lib/SimpleSAML/Session.php
+++ b/lib/SimpleSAML/Session.php
@@ -215,6 +215,9 @@ class SimpleSAML_Session
         if ($sessionId === null) {
             $checkToken = true;
             $sessionId = $sh->getCookieSessionId();
+            if ($sessionId === null) {
+                return null;
+            }
         } else {
             $checkToken = false;
         }