diff --git a/Lib/idlelib/idle_test/__init__.py b/Lib/idlelib/idle_test/__init__.py
index 1bc953643e1..845c92d372a 100644
--- a/Lib/idlelib/idle_test/__init__.py
+++ b/Lib/idlelib/idle_test/__init__.py
@@ -1,3 +1,9 @@
+'''idlelib.idle_test is a private implementation of test.test_idle,
+which tests the IDLE application as part of the stdlib test suite.
+Run IDLE tests alone with "python -m test.test_idle".
+This package and its contained modules are subject to change and
+any direct use is at your own risk.
+'''
 from os.path import dirname
 
 def load_tests(loader, standard_tests, pattern):