diff --git a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/Issuer/OpenIDConnect.pm b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/Issuer/OpenIDConnect.pm
index a0c1618fa..61c9aeef7 100644
--- a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/Issuer/OpenIDConnect.pm
+++ b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/Issuer/OpenIDConnect.pm
@@ -2028,8 +2028,9 @@ sub checkSession {
 
 sub badAuthRequest {
     my ( $self, $req ) = @_;
-    return $self->p->sendError( $req,
-        $req->uri . ' may not be called by an authenticated user', 400 );
+    my $desc =
+      "This endpoint is not supposed to be called by authenticated users";
+    return $self->sendOIDCError( $req, 'invalid_request', 400, $desc );
 }
 
 # Nothing to do here