diff --git a/www/index.php b/www/index.php
index 7658dae..ef18cf1 100644
--- a/www/index.php
+++ b/www/index.php
@@ -415,7 +415,7 @@ try
             ->setName( 'series_of_letters' );
         $router->add
             (
-                '/series_of_letter/:action',
+                '/series_of_letter/:action/{id:[0-9]+?}',
                 [
                     'controller'    => 'series_of_letters',
                     'action'        => 1,
--
libgit2 0.21.4