diff --git a/ansible/roles/kolla-ansible/templates/requirements.txt.j2 b/ansible/roles/kolla-ansible/templates/requirements.txt.j2
index 71325f5b9..583728426 100644
--- a/ansible/roles/kolla-ansible/templates/requirements.txt.j2
+++ b/ansible/roles/kolla-ansible/templates/requirements.txt.j2
@@ -5,4 +5,6 @@
 # Install Kolla Ansible from PyPI.
 kolla-ansible=={{ kolla_openstack_release }}
 {% endif %}
+# Limit the version of ansible used by kolla-ansible to avoid new releases from
+# breaking tested code. Changes to this limit should be tested.
 ansible<2.4