diff --git a/zuul/ansible/base/callback/zuul_unreachable.py b/zuul/ansible/base/callback/zuul_unreachable.py
index 8c7b85f430..ba63bc62c3 100644
--- a/zuul/ansible/base/callback/zuul_unreachable.py
+++ b/zuul/ansible/base/callback/zuul_unreachable.py
@@ -19,6 +19,16 @@
 # so just put in the __future__ statement.
 from __future__ import absolute_import
 
+DOCUMENTATION = '''
+     callback: zuul_unreachable
+     short_description: Zuul Unreachable
+     description:
+         - Zuul Unreachable
+     type: aggregate
+     extends_documentation_fragment:
+       - default_callback
+'''
+
 import os
 
 from ansible.plugins.callback import default