diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index a25fd54..640ed4b 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -208,6 +208,10 @@
 
    python -m unittest -v test_module
 
+When executed without arguments :ref:`unittest-test-discovery` is started::
+
+   python -m unittest
+
 For a list of all the command-line options::
 
    python -m unittest -h
@@ -266,6 +270,12 @@
    cd project_directory
    python -m unittest discover
 
+.. note::
+
+   As a shortcut, ``python -m unittest`` is the equivalent of
+   ``python -m unittest discover``. If you want to pass arguments to test
+   discovery the `discover` sub-command must be used explicitly.
+
 The ``discover`` sub-command has the following options:
 
 .. program:: unittest discover