diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8865f07..776ccff 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -39,7 +39,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - uses: ruby/setup-ruby@v1
+      - uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1
         env:
           RSPEC_CORE: ${{ matrix.rspec-core-version }}
         with: