diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3db09b6..6828a6d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [4.0.0] - 2026-09-19
 
 ### Fixed
 
diff --git a/CITATION.cff b/CITATION.cff
index 69ea1a6..02c370e 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -7,17 +7,14 @@ authors:
   - family-names: Denyer
     given-names: Michael
     email: code.denyer@gmail.com
-version: 3.1.1
-date-released: 2026-09-08
+version: 4.0.0
+date-released: 2026-09-19
 license: GPL-3.0-or-later
 doi: 10.5281/zenodo.22665975
 identifiers:
   - type: doi
     value: 10.5281/zenodo.22665975
     description: Concept DOI, resolves to the latest version
-  - type: doi
-    value: 10.5281/zenodo.22665976
-    description: Version DOI for 3.1.1
 repository-code: https://github.com/michael-denyer/pyLocusZoom
 url: https://github.com/michael-denyer/pyLocusZoom
 keywords:
diff --git a/pyproject.toml b/pyproject.toml
index a680bab..ba9a87f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "pylocuszoom"
-version = "3.1.1"
+version = "4.0.0"
 description = "Publication-ready regional association plots with LD coloring, gene tracks, and recombination overlays"
 readme = "README.md"
 license = "GPL-3.0-or-later"
diff --git a/uv.lock b/uv.lock
index 5180a7a..533afce 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1593,7 +1593,7 @@ wheels = [
 
 [[package]]
 name = "pylocuszoom"
-version = "3.1.1"
+version = "4.0.0"
 source = { editable = "." }
 dependencies = [
     { name = "adjusttext" },