diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0c165083..608395f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+---
+
+## [0.3.1] - 2022-03-01
+
 ### Changed
 
 - Argument parameter `--decoy_string_position` is changed to `--decoy-string-position`. #417
diff --git a/moPepGen/__init__.py b/moPepGen/__init__.py
index 2a8547c6..1b29c00d 100644
--- a/moPepGen/__init__.py
+++ b/moPepGen/__init__.py
@@ -5,7 +5,7 @@
 from typing import Iterable, IO
 
 
-__version__ = '0.3.0'
+__version__ = '0.3.1'
 
 ## Error messages
 ERROR_INDEX_IN_INTRON = 'The genomic index seems to be in an intron'