diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38ace91..27327d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ All notable changes to this project are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html) (as of version 1.5.0).
 
+## [Unreleased]
+
 ## [5.1.0] - 2025-01-21
 
 ### Changed
diff --git a/src/zimscraperlib/__about__.py b/src/zimscraperlib/__about__.py
index 0d72820..41bdee4 100644
--- a/src/zimscraperlib/__about__.py
+++ b/src/zimscraperlib/__about__.py
@@ -1 +1 @@
-__version__ = "5.1.0"
+__version__ = "5.1.1-dev0"