diff --git a/CHANGES.md b/CHANGES.md
index 44d5465..5dbefd4 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,11 @@
 # opensensmapr changelog
 This project does its best to adhere to semantic versioning.
 
+### 2019-02-09: v0.5.1
+- fix package to work with API v6
+  - box$lastMeasurement may be missing now for long inactive boxes
+- add tests
+
 ### 2018-10-20: v0.5.0
 - fix dynamic method export
 - add `osem_measurements_archive()` to fetch measurements from the archive (#23)
diff --git a/DESCRIPTION b/DESCRIPTION
index c1485b6..f3a9fed 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: opensensmapr
 Type: Package
 Title: Client for the Data API of openSenseMap.org
-Version: 0.5.0
+Version: 0.5.1
 URL: http://github.com/sensebox/opensensmapR
 BugReports: http://github.com/sensebox/opensensmapR/issues
 Imports: