diff --git a/.github/workflows/claude-code-agent.yml b/.github/workflows/claude-code-agent.yml
index 0d2c10c..bc8ec6e 100644
--- a/.github/workflows/claude-code-agent.yml
+++ b/.github/workflows/claude-code-agent.yml
@@ -27,7 +27,7 @@ jobs:
       actions: read # Required for Claude to read CI results on PRs
     steps:
       - name: Checkout repository
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
         with:
           fetch-depth: 1
 
diff --git a/.github/workflows/claude-code-review.yml b/.github/workflows/claude-code-review.yml
index c44654a..ea1d547 100644
--- a/.github/workflows/claude-code-review.yml
+++ b/.github/workflows/claude-code-review.yml
@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
         with:
           fetch-depth: 1
 
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index fe25c95..bb43fb7 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -14,7 +14,7 @@ jobs:
         language: [rust, shell]
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Check formatting.
         run: make check-${{ matrix.language }}-formatting
   linting:
@@ -25,7 +25,7 @@ jobs:
         language: [rust]
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Check linting.
         run: make check-${{ matrix.language }}-linting
   compile:
@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Compile.
         run: make compile
   unit-test:
@@ -41,6 +41,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Unit test.
         run: make unit-test
diff --git a/.github/workflows/conventional-commits.yml b/.github/workflows/conventional-commits.yml
index 5944eb5..158ec46 100644
--- a/.github/workflows/conventional-commits.yml
+++ b/.github/workflows/conventional-commits.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
diff --git a/.github/workflows/git-history.yml b/.github/workflows/git-history.yml
index 0d42952..df7c33e 100644
--- a/.github/workflows/git-history.yml
+++ b/.github/workflows/git-history.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
diff --git a/.github/workflows/github-actions-workflows.yml b/.github/workflows/github-actions-workflows.yml
index f997742..843d47c 100644
--- a/.github/workflows/github-actions-workflows.yml
+++ b/.github/workflows/github-actions-workflows.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Check GitHub Actions workflows linting.
         run: make check-github-actions-workflows-linting
   formatting:
@@ -19,6 +19,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code.
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Check formatting.
         run: make check-yaml-formatting