diff --git a/.github/workflows/pdd.yml b/.github/workflows/pdd.yml
index 16fca4a..033db95 100644
--- a/.github/workflows/pdd.yml
+++ b/.github/workflows/pdd.yml
@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.3
+          ruby-version: 4.0.6
       - run: sudo apt-get update && sudo apt-get install -y libmagic-dev
       - run: gem install pdd
       - run: pdd --file=/dev/null