diff --git a/service_container/tags.rst b/service_container/tags.rst
index c6cecfcd288..ffac1487a77 100644
--- a/service_container/tags.rst
+++ b/service_container/tags.rst
@@ -69,6 +69,8 @@ that it implements ``Twig_ExtensionInterface``) and adds the tag for you.
     interface, call the :method:`Symfony\\Component\\DependencyInjection\\ContainerBuilder::registerForAutoconfiguration`
     method in an :doc:`extension </bundles/extension>` or from your kernel::
 
+    .. code-block:: php
+
         // app/AppKernel.php
         class AppKernel extends Kernel
         {
@@ -82,6 +84,16 @@ that it implements ``Twig_ExtensionInterface``) and adds the tag for you.
             }
         }
 
+    If you do not want to create a custom kernel, it is also possible to use `_instanceof`:
+
+    .. code-block:: yaml
+
+        // app/config/services.yml
+        services:
+            _instanceof:
+                AppBundle\Component\CustomInterface:
+                    tags: ['app.custom_tag']
+
 Creating custom Tags
 --------------------