diff --git a/jenkins/scripts/run-docs.sh b/jenkins/scripts/run-docs.sh
index 7f833770bb..a6ae55f233 100755
--- a/jenkins/scripts/run-docs.sh
+++ b/jenkins/scripts/run-docs.sh
@@ -11,6 +11,10 @@ venv=venv
 
 mkdir -p doc/build
 export HUDSON_PUBLISH_DOCS=1
+# The "python setup.py build_sphinx" is intentionally executed instead of
+# "tox -edocs", because it's the standard python project build interface
+# specified in OpenStack Project Testing Interface:
+# http://governance.openstack.org/reference/project-testing-interface.html
 tox -e$venv -- python setup.py build_sphinx
 result=$?