diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index 6ac4eff..568a780 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v6.0.0
       - name: Setup Ruby
         uses: ruby/setup-ruby@d5126b9b3579e429dd52e51e68624dda2e05be25 # v1.267.0
         with:
diff --git a/.github/workflows/push_gem.yml b/.github/workflows/push_gem.yml
index 341403a..3d8d849 100644
--- a/.github/workflows/push_gem.yml
+++ b/.github/workflows/push_gem.yml
@@ -27,7 +27,7 @@ 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
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ac25f09..43f9e42 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -20,7 +20,7 @@ jobs:
             os: macos-latest
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.0
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with: