diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 883a5c4..a7d47e9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -52,7 +52,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1.312.0
       with:
-        ruby-version: '3.4'
+        ruby-version: '4.0'
         bundler-cache: true
 
     - name: Run StandardRB
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a481ff..d116e2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Run StandardRB linting on Ruby 4.0 (was 3.4)
+
 ## [0.2.0] - 2026-03-23
 
 ### Added