diff --git a/tox.ini b/tox.ini
index e3ebd1e5f..cd49b3c86 100644
--- a/tox.ini
+++ b/tox.ini
@@ -127,6 +127,7 @@ setenv=
   # only available for ansible >= 2.2
   ANSIBLE_STDOUT_CALLBACK = debug
   docker_cluster: PLAYBOOK = site-docker.yml.sample
+  docker_cluster_collocation: PLAYBOOK = site-docker.yml.sample
   update_docker_cluster: PLAYBOOK = site-docker.yml.sample
   purge_docker_cluster: PLAYBOOK = site-docker.yml.sample
   purge_docker_cluster: PURGE_PLAYBOOK = purge-docker-cluster.yml