use .. instead of .. code-block:: php

Author: OskarStark

components/config/definition.rst

@@ -403,7 +403,7 @@ has a certain value:
     (``null``, ``true``, ``false``), provide a replacement value in case
     the value is ``*.``
 
-.. code-block:: php
+You can find any of these in the following code example::
 
     $rootNode
         ->children()