diff --git a/doc/api/core.rst b/doc/api/core.rst
index 044ef8c9d6c9de2923619d92cfddb9a386d94f32..35ad7f12fb421256fc14c274956568e1ae5a450b 100644
--- a/doc/api/core.rst
+++ b/doc/api/core.rst
@@ -1,12 +1,16 @@
 Core library
 ------------
 
-Sub-packages:
-
 .. toctree::
-   :maxdepth: 2
+ :maxdepth: 2
+ :hidden:
+
+ core.protocols
+
+.. seealso::
+
+  API documentation on the sub-package :doc:`core.protocols`.
 
-   core.protocols
 
 .. automodule:: sjrpc.core
    :members: