diff --git a/modules/discopower/lib/PowerIdPDisco.php b/modules/discopower/lib/PowerIdPDisco.php
index 10aad002f4e8dc62106da0ba069cc58a4bc2d87e..75a624832144736ca041908f4cb6cfbd1447b327 100644
--- a/modules/discopower/lib/PowerIdPDisco.php
+++ b/modules/discopower/lib/PowerIdPDisco.php
@@ -190,7 +190,7 @@ class sspmod_discopower_PowerIdPDisco extends SimpleSAML_XHTML_IdPDisco {
 		$idp = $this->getTargetIdp();
 		if($idp !== NULL) {
 
-			$extDiscoveryStorage = $this->config->getString('idpdisco.extDiscoveryStorage');
+			$extDiscoveryStorage = $this->config->getString('idpdisco.extDiscoveryStorage',NULL);
 			if ($extDiscoveryStorage !== NULL) {
 				$this->log('Choice made [' . $idp . '] (Forwarding to external discovery storage)');
 				SimpleSAML_Utilities::redirectTrustedURL($extDiscoveryStorage, array(