diff --git a/examples/playbook.yml b/examples/playbook.yml
index 5301f5fa..a40e8e40 100644
--- a/examples/playbook.yml
+++ b/examples/playbook.yml
@@ -1,3 +1,4 @@
+---
 - name: Installation and setup of horizon
   hosts: horizon_all
   user: root
diff --git a/tests/ansible-role-requirements.yml b/tests/ansible-role-requirements.yml
index 0929a66a..8da56d65 100644
--- a/tests/ansible-role-requirements.yml
+++ b/tests/ansible-role-requirements.yml
@@ -1,3 +1,4 @@
+---
 - name: apt_package_pinning
   src: https://git.openstack.org/openstack/openstack-ansible-apt_package_pinning
   scm: git
diff --git a/zuul.d/project.yaml b/zuul.d/project.yaml
index 62bbfb2a..66bf1e5d 100644
--- a/zuul.d/project.yaml
+++ b/zuul.d/project.yaml
@@ -1,3 +1,4 @@
+---
 # Copyright 2017, Rackspace US, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");