diff --git a/README.rst b/README.rst
index 08bd72a..966b6b7 100644
--- a/README.rst
+++ b/README.rst
@@ -68,6 +68,7 @@
           timeout: 900
           logfile: /var/log/elasticsearch/curator.log
           logformat: json
+          master_only: true
           actions:
             - action: delete_indices
               description: >-