Fixes broken rst ref. Closes #1998

docs/userguide/calling.rst

@@ -318,7 +318,12 @@ or for each individual task, or even per message.
 
 There's built-in support for :mod:`pickle`, `JSON`, `YAML`
 and `msgpack`, and you can also add your own custom serializers by registering
-them into the Kombu serializer registry (see ref:`kombu:guide-serialization`).
+them into the Kombu serializer registry
+
+.. seealso::
+
+    :ref:`Message Serialization <kombu:guide-serialization>` in the Kombu user
+    guide.
 
 Each option has its advantages and disadvantages.