diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index df70514..3366c91 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     steps:
     - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
     - name: Set up Ruby
-      uses: ruby/setup-ruby@v1
+      uses: ruby/setup-ruby@4c24fa5ec04b2e79eb40571b1cee2a0d2b705771 # v1.278.0
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically