diff --git a/docs/source/publishing-docs.rst b/docs/source/publishing-docs.rst
index 0c682db..e9d8afe 100644
--- a/docs/source/publishing-docs.rst
+++ b/docs/source/publishing-docs.rst
@@ -15,6 +15,12 @@ We recommend `doctr <https://drdoctr.github.io/doctr/>`_ a tool that configures
 Travis-CI to automatically publish your documentation every time the master
 branch is updated.
 
+.. warning::
+    The repo you want to build the docs for has to be a root repo.
+    You cannot build docs for a forked repo by doctr yet.
+    The doctr team is working on enabling a forked repo build under
+    `PR #343 <https://github.com/drdoctr/doctr/pull/343>`_.
+
 Install doctr.
 
    .. code-block:: bash