diff --git a/.github/workflows/api-misskey-js.yml b/.github/workflows/api-misskey-js.yml
index 7b8a1ce128..4cf523a6b9 100644
--- a/.github/workflows/api-misskey-js.yml
+++ b/.github/workflows/api-misskey-js.yml
@@ -9,7 +9,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
 
       - run: corepack enable
 
diff --git a/.github/workflows/check_copyright_year.yml b/.github/workflows/check_copyright_year.yml
index e06e33b397..313265f671 100644
--- a/.github/workflows/check_copyright_year.yml
+++ b/.github/workflows/check_copyright_year.yml
@@ -10,7 +10,7 @@ jobs:
   check_copyright_year:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
     - run: |
         if [ "$(grep Copyright COPYING | sed -e 's/.*2014-\([0-9]*\) .*/\1/g')" -ne "$(date +%Y)" ]; then
           echo "Please change copyright year!"
diff --git a/.github/workflows/docker-develop.yml b/.github/workflows/docker-develop.yml
index f51e80f995..d7f02fd8f3 100644
--- a/.github/workflows/docker-develop.yml
+++ b/.github/workflows/docker-develop.yml
@@ -13,7 +13,7 @@ jobs:
     if: github.repository == 'misskey-dev/misskey'
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
       - name: Set up Docker Buildx
         id: buildx
         uses: docker/setup-buildx-action@v2.10.0
diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 70ebd66e26..e142e0915b 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
       - name: Set up Docker Buildx
         id: buildx
         uses: docker/setup-buildx-action@v2.10.0
diff --git a/.github/workflows/dockle.yml b/.github/workflows/dockle.yml
index 4e90b4fc3d..d811944d61 100644
--- a/.github/workflows/dockle.yml
+++ b/.github/workflows/dockle.yml
@@ -14,7 +14,7 @@ jobs:
     env:
       DOCKER_CONTENT_TRUST: 1
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
       - run: |
           curl -L -o dockle.deb "https://github.com/goodwithtech/dockle/releases/download/v0.4.10/dockle_0.4.10_Linux-64bit.deb"
           sudo dpkg -i dockle.deb
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index ae40a274a9..7c10c23e77 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -11,7 +11,7 @@ jobs:
   pnpm_install:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         fetch-depth: 0
         submodules: true
@@ -38,7 +38,7 @@ jobs:
         - sw
         - misskey-js
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         fetch-depth: 0
         submodules: true
@@ -64,7 +64,7 @@ jobs:
         - backend
         - misskey-js
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         fetch-depth: 0
         submodules: true
diff --git a/.github/workflows/pr-preview-deploy.yml b/.github/workflows/pr-preview-deploy.yml
index 7980b7383c..702d8917e3 100644
--- a/.github/workflows/pr-preview-deploy.yml
+++ b/.github/workflows/pr-preview-deploy.yml
@@ -53,7 +53,7 @@ jobs:
 
     # Check out merge commit
     - name: Fork based /deploy checkout
-      uses: actions/checkout@v3.6.0
+      uses: actions/checkout@v4.0.0
       with:
         ref: 'refs/pull/${{ github.event.client_payload.pull_request.number }}/merge'
 
diff --git a/.github/workflows/test-backend.yml b/.github/workflows/test-backend.yml
index 1d9e613433..3a3e278631 100644
--- a/.github/workflows/test-backend.yml
+++ b/.github/workflows/test-backend.yml
@@ -29,7 +29,7 @@ jobs:
           - 56312:6379
 
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         submodules: true
     - name: Install pnpm
diff --git a/.github/workflows/test-frontend.yml b/.github/workflows/test-frontend.yml
index 0a7f954fde..998a191611 100644
--- a/.github/workflows/test-frontend.yml
+++ b/.github/workflows/test-frontend.yml
@@ -16,7 +16,7 @@ jobs:
         node-version: [20.x]
 
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         submodules: true
     - name: Install pnpm
@@ -68,7 +68,7 @@ jobs:
           - 56312:6379
 
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         submodules: true
     # https://github.com/cypress-io/cypress-docker-images/issues/150
diff --git a/.github/workflows/test-misskey-js.yml b/.github/workflows/test-misskey-js.yml
index a3be6216e1..d1d3013a2b 100644
--- a/.github/workflows/test-misskey-js.yml
+++ b/.github/workflows/test-misskey-js.yml
@@ -21,7 +21,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
 
       - run: corepack enable
 
diff --git a/.github/workflows/test-production.yml b/.github/workflows/test-production.yml
index 07a33ac357..16517d137e 100644
--- a/.github/workflows/test-production.yml
+++ b/.github/workflows/test-production.yml
@@ -19,7 +19,7 @@ jobs:
         node-version: [20.x]
 
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
       with:
         submodules: true
     - name: Install pnpm