diff --git a/.github/workflows/build-site.yml b/.github/workflows/build-site.yml
index 69df895d..ea5f6cd4 100644
--- a/.github/workflows/build-site.yml
+++ b/.github/workflows/build-site.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Fetch main
         run: |
diff --git a/.github/workflows/deploy-gh-pages.yml b/.github/workflows/deploy-gh-pages.yml
index b5de1226..5275ecc2 100644
--- a/.github/workflows/deploy-gh-pages.yml
+++ b/.github/workflows/deploy-gh-pages.yml
@@ -32,7 +32,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
         with:
diff --git a/.github/workflows/linkcheck.yml b/.github/workflows/linkcheck.yml
index a8dec236..00e95d17 100644
--- a/.github/workflows/linkcheck.yml
+++ b/.github/workflows/linkcheck.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Fetch main
         run: |
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e96f467d..1f0dbcd9 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -11,7 +11,7 @@ jobs:
     name: Action lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Check workflow files
         run: |
           bash <(curl https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
diff --git a/.github/workflows/update-contribs-reviews.yml b/.github/workflows/update-contribs-reviews.yml
index 99551763..506d9237 100644
--- a/.github/workflows/update-contribs-reviews.yml
+++ b/.github/workflows/update-contribs-reviews.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Python
         uses: actions/setup-python@v6
         with: