diff --git a/tests/test-demandimport.py b/tests/test-demandimport.py
--- a/tests/test-demandimport.py
+++ b/tests/test-demandimport.py
@@ -65,6 +65,7 @@ print("re =", f(re))
 
 demandimport.disable()
 os.environ['HGDEMANDIMPORT'] = 'disable'
+# this enable call should not actually enable demandimport!
 demandimport.enable()
 from mercurial import node
 print("node =", f(node))