diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 90319f6..74f79c7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,7 +17,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.4.7'
+          ruby-version: '4.0.2'
       - name: Install gems
         run: bundle install
       - name: Generate ruby
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 29b099d..84defbb 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -25,7 +25,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.4.7'
+          ruby-version: '4.0.2'
       - name: Install gems
         run: bundle install
       - name: Set version
diff --git a/build/ruby/.tool-versions b/build/ruby/.tool-versions
index 3f03c7a..0f1e605 100644
--- a/build/ruby/.tool-versions
+++ b/build/ruby/.tool-versions
@@ -1 +1 @@
-ruby 3.4.7
+ruby 4.0.2