diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cc82570..95837cc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,7 +39,7 @@ jobs:
         - { os: windows-latest, ruby: head }
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v6.0.0
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
diff --git a/.github/workflows/push_gem.yml b/.github/workflows/push_gem.yml
index 0e57db1..ec47dbe 100644
--- a/.github/workflows/push_gem.yml
+++ b/.github/workflows/push_gem.yml
@@ -31,7 +31,7 @@ jobs:
         with:
           egress-policy: audit
 
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+      - uses: actions/checkout@c2d88d3ecc89a9ef08eebf45d9637801dcee7eb5 # v5.0.1
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@d5126b9b3579e429dd52e51e68624dda2e05be25 # v1.267.0
diff --git a/.github/workflows/sync-ruby.yml b/.github/workflows/sync-ruby.yml
index 78e94eb..fa68ec6 100644
--- a/.github/workflows/sync-ruby.yml
+++ b/.github/workflows/sync-ruby.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository_owner == 'ruby' }}
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v6.0.0
 
       - name: Create GitHub App token
         id: app-token