diff --git a/tempest/tests/test_decorators.py b/tempest/tests/test_decorators.py
index 2fc84dc..e3e21f9 100644
--- a/tempest/tests/test_decorators.py
+++ b/tempest/tests/test_decorators.py
@@ -31,6 +31,10 @@
                          fake_config.FakePrivate)
 
 
+# NOTE: The test module is for tempest.test.idempotent_id.
+# After all projects switch to use decorators.idempotent_id,
+# we can remove tempest.test.idempotent_id as well as this
+# test module
 class TestIdempotentIdDecorator(BaseDecoratorsTest):
 
     def _test_helper(self, _id, **decorator_args):