diff --git a/doc/14-features.md b/doc/14-features.md
index e2fdeb591..316707a3e 100644
--- a/doc/14-features.md
+++ b/doc/14-features.md
@@ -347,7 +347,7 @@ The check results include parsed performance data metrics if enabled.
 
 > **Note**
 >
-> Elasticsearch 5.x+ is required.
+> Elasticsearch 5.x+ is required. This feature has been tested with Elasticsearch 5.6.4 and 6.0.0.
 
 Enable the feature and restart Icinga 2.