diff --git a/app/Config/saml2.php b/app/Config/saml2.php
index 5f2c1395b..d695abf32 100644
--- a/app/Config/saml2.php
+++ b/app/Config/saml2.php
@@ -101,7 +101,7 @@ return [
                 'url' => env('SAML2_IDP_SLO', null),
                 // URL location of the IdP where the SP will send the SLO Response (ResponseLocation)
                 // if not set, url for the SLO Request will be used
-                'responseUrl' => '',
+                'responseUrl' => null,
                 // SAML protocol binding to be used when returning the <Response>
                 // message.  Onelogin Toolkit supports for this endpoint the
                 // HTTP-Redirect binding only