diff --git a/modules/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/IssuerDBCAS.pm b/modules/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/IssuerDBCAS.pm
index e4ef9f476..d5ebc6bc7 100644
--- a/modules/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/IssuerDBCAS.pm
+++ b/modules/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/IssuerDBCAS.pm
@@ -583,10 +583,11 @@ sub issuerForAuthUser {
             'debug' );
 
         # Redirect to service
-        my $service_url = (
+        my $service_url = $service;
+        $service_url .= (
               $service =~ /\?/
-            ? $service .= '&ticket=' . $casServiceTicket
-            : $service .= '?ticket=' . $casServiceTicket
+            ? '&ticket=' . $casServiceTicket
+            : '?ticket=' . $casServiceTicket
         );
 
         $self->lmLog( "Redirect user to $service_url", 'debug' );