diff --git a/elasticsearch/README.md b/elasticsearch/README.md
index ce7e6b72..176a70c3 100644
--- a/elasticsearch/README.md
+++ b/elasticsearch/README.md
@@ -21,3 +21,5 @@ Tasks are extracted in several files, included in `tasks/main.yml` :
 * `elasticsearch_network_publish_host`: which interface to publish ;
 * `elasticsearch_custom_datadir`: custom datadir
 * `elasticsearch_custom_tmpdir`: custom tmpdir
+
+By default, Elasticsearch will listen to the public interfaces (`_site_` cf. https://www.elastic.co/guide/en/elasticsearch/reference/5.0/important-settings.html#network.host), so you will have to secure it, with firewall rules for example.