diff --git a/backend/CHANGELOG.md b/backend/CHANGELOG.md
index f3b8f47..a76b4e6 100644
--- a/backend/CHANGELOG.md
+++ b/backend/CHANGELOG.md
@@ -14,6 +14,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 <!-- ### Fixed -->
 
 
+## Unreleased [2.0.0 - 2019-04-XX]
+### Changed
+* require Elasticsearch 6.x
+* move data structure to single document per index 
+
 ## [1.2.0 - 2019-03-17]
 ### Changed
 * Replaced elasticsearch client
diff --git a/backend/README.md b/backend/README.md
index 0a21481..19d0e2c 100644
--- a/backend/README.md
+++ b/backend/README.md
@@ -13,8 +13,8 @@ Manual Installation
 To run the app you need to have meet prerequsites:
 
 - python 3.5+
-- running elasticsearch (2.3+/2.4 tested)
-- running postgresql (9.5+ required)
+- running elasticsearch (6.6.2 tested)
+- running postgresql (9.5+ required, tested 9.6 and 10.6)
 - running redis
 
 Install the app by performing