diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ffce818..723a8c1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -30,6 +30,8 @@ jobs:
           gemfile: Gemfile
         - ruby: 3.4.1
           gemfile: Gemfile
+        - ruby: 4.0.1
+          gemfile: Gemfile
     env:
       BUNDLE_GEMFILE: "${{ matrix.gemfile }}"
     steps:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 908d6e4..0e1acd5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,9 +8,8 @@ This project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html
 ### Breaking changes
 
 ### Compatible changes
+- Add support for Ruby 4.0
 
-- Add support for Ruby 3.3
-- Add support for Ruby 3.4
 
 ## 3.2.0 - 2023-03-01
 
diff --git a/modularity.gemspec b/modularity.gemspec
index 77d626f..91837e1 100755
--- a/modularity.gemspec
+++ b/modularity.gemspec
@@ -5,7 +5,7 @@ require 'modularity/version'
 Gem::Specification.new do |spec|
   spec.name = 'modularity'
   spec.version = Modularity::VERSION
-  spec.required_ruby_version = '>= 2.5.0'
+  spec.required_ruby_version = '>= 2.5.7'
   spec.authors = ['Henning Koch']
   spec.email = ['henning.koch@makandra.de']