diff --git a/config.rst b/config.rst
index c1a553b..2a07307 100644
--- a/config.rst
+++ b/config.rst
@@ -116,7 +116,7 @@ always optimal, however, and you can customize that behavior on any application
 container or on any service.
 
 Legal values for the size key are ``AUTO`` (the default), ``S``, ``M``, ``L``,
-and ``XL``.
+``XL``, ``2XL`` and ``4XL``.
 
 .. note::