diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f336cd2..2a2ad03 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     name: Ruby ${{ matrix.ruby }} CI
     steps:
       - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
-      - uses: ruby/setup-ruby@v1
+      - uses: ruby/setup-ruby@95ef2b042f9d7a56d8268cba8559e2842e2ad01b # v1.321.0
         with:
           ruby-version: ${{ matrix.ruby }}
       - run: bundle install