diff --git a/.github/workflows/cloudflare-preview.yml b/.github/workflows/cloudflare-preview.yml
index b1f7c2df47..f46376d441 100644
--- a/.github/workflows/cloudflare-preview.yml
+++ b/.github/workflows/cloudflare-preview.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout PR Code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v6.0.0
         with:
           repository: ${{ github.event.client_payload.pr_checkout_repository }}
           ref: ${{ github.event.client_payload.pr_head_sha }}
diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index ffa0b922d2..62a3667e56 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -20,7 +20,7 @@ jobs:
     if: ${{ github.repository == 'ruby/rdoc' && !startsWith(github.event_name, 'pull') }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v6.0.0
       - name: Setup Ruby
         uses: ruby/setup-ruby@eaecf785f6a34567a6d97f686bbb7bccc1ac1e5c # v1.237.0
         with:
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 8f70de35e6..71695f9582 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6 # v3.3.0
+    - uses: actions/checkout@v6.0.0 # v3.3.0
     # libyaml-dev is needed for psych, see https://github.com/ruby/setup-ruby/issues/409
     - if: ${{ matrix.os == 'ubuntu-latest' }}
       run: sudo apt install libyaml-dev
diff --git a/.github/workflows/push_gem.yml b/.github/workflows/push_gem.yml
index 48d6b916bc..334e5dbf0c 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@eaecf785f6a34567a6d97f686bbb7bccc1ac1e5c # v1.237.0
diff --git a/.github/workflows/ruby-core.yml b/.github/workflows/ruby-core.yml
index effedde954..a3b6ce9673 100644
--- a/.github/workflows/ruby-core.yml
+++ b/.github/workflows/ruby-core.yml
@@ -28,7 +28,7 @@ jobs:
           bundler: none
       - name: Save latest buildable revision to environment
         run: echo "REF=$(ruby -v | cut -d')' -f1 | cut -d' ' -f5)" >> $GITHUB_ENV
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v3.1.0
+      - uses: actions/checkout@c2d88d3ecc89a9ef08eebf45d9637801dcee7eb5 # v3.1.0
         with:
           repository: ruby/ruby
           path: ruby/ruby
@@ -51,7 +51,7 @@ jobs:
           autoconf
           ./configure -C --disable-install-doc
         working-directory: ruby/ruby
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v3.1.0
+      - uses: actions/checkout@c2d88d3ecc89a9ef08eebf45d9637801dcee7eb5 # v3.1.0
         with:
           path: ruby/rdoc
       - name: Build RDoc locally
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4c99e1dc9b..8e95cf04fa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -41,7 +41,7 @@ jobs:
 
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v6 # v3.3.0
+    - uses: actions/checkout@v6.0.0 # v3.3.0
     # libyaml-dev is needed for psych, see https://github.com/ruby/setup-ruby/issues/409
     - if: ${{ matrix.os == 'ubuntu-latest' }}
       run: sudo apt install libyaml-dev