diff --git a/docs/api/frontends.rst b/docs/api/frontends.rst
index 58436c03..6da5d337 100644
--- a/docs/api/frontends.rst
+++ b/docs/api/frontends.rst
@@ -13,9 +13,12 @@ The following requirements applies to any frontend implementation:
   <http://pykka.readthedocs.org/>`_ actor, called the "main actor" from here
   on.
 
-- The main actor MUST accept a constructor argument ``core``, which will be an
-  :class:`ActorProxy <pykka.proxy.ActorProxy>` for the core actor. This object
-  gives access to the full :ref:`core-api`.
+- The main actor MUST accept two constructor arguments:
+
+  - ``config``, which is a dict structure with the entire Mopidy configuration.
+
+  - ``core``, which will be an :class:`ActorProxy <pykka.proxy.ActorProxy>` for
+    the core actor. This object gives access to the full :ref:`core-api`.
 
 - It MAY use additional actors to implement whatever it does, and using actors
   in frontend implementations is encouraged.