diff --git a/Doc/library/test.rst b/Doc/library/test.rst
index b21e177..88f0397 100644
--- a/Doc/library/test.rst
+++ b/Doc/library/test.rst
@@ -6,6 +6,13 @@
    :synopsis: Regression tests package containing the testing suite for Python.
 .. sectionauthor:: Brett Cannon <brett@python.org>
 
+.. note::
+    The :mod:`test` package is meant for internal use by Python only. It is
+    documented for the benefit of the core developers of Python. Any use of
+    this package outside of Python's standard library is discouraged as code
+    mentioned here can change or be removed without notice between releases of
+    Python.
+
 
 The :mod:`test` package contains all regression tests for Python as well as the
 modules :mod:`test.test_support` and :mod:`test.regrtest`.