diff --git a/.github/workflows/depup.yml b/.github/workflows/depup.yml
index 30cefce..3284ac4 100644
--- a/.github/workflows/depup.yml
+++ b/.github/workflows/depup.yml
@@ -9,7 +9,7 @@ jobs:
   reviewdog:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: haya14busa/action-depup@v1
         id: depup
         with:
diff --git a/.github/workflows/dockerimage.yml b/.github/workflows/dockerimage.yml
index 041026f..d7c22a8 100644
--- a/.github/workflows/dockerimage.yml
+++ b/.github/workflows/dockerimage.yml
@@ -9,6 +9,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
     - name: Build the Docker image
       run: docker build . --file Dockerfile --tag reviewdog-misspell:$(date +%s)
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9dd2136..2f519d8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -14,7 +14,7 @@ jobs:
     if: github.event.action != 'labeled'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       # Bump version on merging Pull Requests with specific labels.
       # (bump:major,bump:minor,bump:patch)
@@ -50,6 +50,6 @@ jobs:
     if: github.event.action == 'labeled'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - name: Post bumpr status comment
         uses: haya14busa/action-bumpr@v1
diff --git a/.github/workflows/reviewdog.yml b/.github/workflows/reviewdog.yml
index 8aa81bf..b4c01bb 100644
--- a/.github/workflows/reviewdog.yml
+++ b/.github/workflows/reviewdog.yml
@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code.
-        uses: actions/checkout@v3
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - name: misspell
         uses: ./
         with:
diff --git a/.github/workflows/update_semver.yml b/.github/workflows/update_semver.yml
index 24db7ff..e2150c8 100644
--- a/.github/workflows/update_semver.yml
+++ b/.github/workflows/update_semver.yml
@@ -9,7 +9,7 @@ jobs:
   update-semver:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: haya14busa/action-update-semver@v1
         with:
           github_token: ${{ secrets.github_token }}