diff --git a/.github/workflows/rubocop.yaml b/.github/workflows/rubocop.yaml
index db9a5014..11220aa6 100644
--- a/.github/workflows/rubocop.yaml
+++ b/.github/workflows/rubocop.yaml
@@ -16,7 +16,7 @@ jobs:
     - name: setup ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '3.4.8'
+        ruby-version: '4.0.1'
     - name: cache gems
       uses: actions/cache@v5
       with: