diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 61e1735d..7f7d8895 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -165,7 +165,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.4'
+          ruby-version: '4.0'
           bundler-cache: true
           cache-version: 1
         continue-on-error: ${{ matrix.experimental }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 359de9e7..4f0a2826 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 * [CHORE] ...
 * [FEATURE] ...
 
+* [CHORE] Run Markdown linting in CI using Ruby 4.0 (by [@faisal][])
 * [CHORE] In RubyCritic::Generator::Html::Line, require cgi/escape rather than cgi, as the latter is removed from Ruby 4.0 (by [@faisal][])
 * [CHORE] Start testing library with Ruby 4.0 (by [@etagwerker][])
 * [CHANGE] Add CI support for JRuby 10.0 (by [@faisal][])