diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d717c51..2fe20c4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
         node-version: [20, 22]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v4
@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: lint-and-unit
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
@@ -73,7 +73,7 @@ jobs:
     needs: lint-and-unit
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
diff --git a/.github/workflows/claude.yml b/.github/workflows/claude.yml
index 325026f..9732e80 100644
--- a/.github/workflows/claude.yml
+++ b/.github/workflows/claude.yml
@@ -26,7 +26,7 @@ jobs:
       actions: read # Required for Claude to read CI results on PRs
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1
 
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index a610b67..2925369 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -13,7 +13,7 @@ jobs:
   lint-and-unit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: lint-and-unit
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
@@ -58,7 +58,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: lint-and-unit
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
@@ -81,7 +81,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [integration-mock, integration-real]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Use Node.js 22
         uses: actions/setup-node@v4
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index d9823f7..adf3a1e 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -11,7 +11,7 @@ jobs:
   security:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.event.pull_request.head.sha || github.sha }}
           fetch-depth: 2