diff --git a/README.rst b/README.rst
index a396daa0a..8f1e95b91 100644
--- a/README.rst
+++ b/README.rst
@@ -12,7 +12,7 @@ By `Leandro Toledo <leandrotoledodesouza@gmail.com>`_
 Introduction
 ============
 
-This library provides a pure Python interface for the `Telegram Bot API <https://core.telegram.org/bots/api>`_. It works with Python versions from 2.6+. Python 3 support is under development. It also works with `Google App Engine <https://cloud.google.com/appengine>`_.
+This library provides a pure Python interface for the `Telegram Bot API <https://core.telegram.org/bots/api>`_. It works with Python versions from 2.6+. Python 3 support is under development. It also works with `Google App Engine <https://cloud.google.com/appengine>`_ (billing has to be enabled for fully Socket API support).
 
 ==========
 Status