diff --git a/CHANGELOG.md b/CHANGELOG.md
index 329a801..6339481 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Change log
 
+## Release 0.5.1 (2023-08-03)
+
+New features:
+
+- New (experimental) command line interface `voc4cat-ng` that will replace the current one in 0.6.0. #128, #135
+- When adding IDs via --make-IDs, the new CLI offers to pass a base-IRI (see help `voc4cat-ng transform --help`).
+
+Changes:
+
+- Various small changes to improve test coverage (now 96 %) and reduce the number of linter complaints (from 38 to 25).
+
 ## Release 0.5.0 (2023-07-27)
 
 New features:
diff --git a/README.md b/README.md
index 8a79b4c..590ee92 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,7 @@ Starting with v0.5.0 (July 2023) voc4cat uses its internal converter and does no
 To start you need:
 
 - git
-- Python (3.8 or newer)
+- Python (3.10 or newer)
 
 voc4cat works on windows, linux and mac. However, the examples below assume that you work on windows
 and that the [launcher](https://docs.python.org/3.11/using/windows.html#python-launcher-for-windows) is installed.
@@ -73,6 +73,8 @@ Show a help message for the voc4cat command line tool with all available options
 
 `voc4cat --help` (or simply `voc4cat`)
 
+*If you feel adventurous, you may alternatively try out the new improved command line interface `voc4cat-ng` (added in Release 0.5.1).*
+
 To create a new vocabulary use the voc4Cat-adjusted template from the `templates` subfolder.
 You may first use simple temporary IRIs like (`ex:my_term`).