diff --git a/modules/discopower/lib/PowerIdPDisco.php b/modules/discopower/lib/PowerIdPDisco.php
index e36816aa693efadc4304e1f1465a5a8e54a0a510..c3d8f19f9d807b7a5c0b3e701b698eb69cfc7ffd 100644
--- a/modules/discopower/lib/PowerIdPDisco.php
+++ b/modules/discopower/lib/PowerIdPDisco.php
@@ -186,7 +186,7 @@ class sspmod_discopower_PowerIdPDisco extends SimpleSAML_XHTML_IdPDisco
      */
     protected function filterList($list)
     {
-        parent::filterList($list);
+        $list = parent::filterList($list);
 
         try {
             $spmd = $this->metadata->getMetaData($this->spEntityId, 'saml20-sp-remote');