diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 1a1a0a2..c006fa8 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -10,7 +10,7 @@ jobs:
   CodeQL-Build:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v1
diff --git a/.github/workflows/dev-image.yml b/.github/workflows/dev-image.yml
index 1fe0f77..4e3c37b 100644
--- a/.github/workflows/dev-image.yml
+++ b/.github/workflows/dev-image.yml
@@ -25,7 +25,7 @@ jobs:
   dev-image-test:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - run: make build
       - run: make cirun cmd="npm ci"
       # - run: make ciall
diff --git a/.github/workflows/label-commenter.yml b/.github/workflows/label-commenter.yml
index b915300..3257579 100644
--- a/.github/workflows/label-commenter.yml
+++ b/.github/workflows/label-commenter.yml
@@ -14,7 +14,7 @@ jobs:
   comment:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
         with:
           ref: main
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 20d2b35..a33f4cb 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,7 +9,7 @@ jobs:
   release:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
 
       - name: Dump GitHub context
         env:
diff --git a/.github/workflows/test-action.yml b/.github/workflows/test-action.yml
index f94efb1..9c8faaf 100644
--- a/.github/workflows/test-action.yml
+++ b/.github/workflows/test-action.yml
@@ -22,7 +22,7 @@ jobs:
           - true
           - false
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
 
       - name: Setup Hugo
         uses: peaceiris/actions-hugo@v2
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4311ec8..88e357f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -21,7 +21,7 @@ jobs:
           - 'macos-latest'
           - 'windows-latest'
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
 
       - name: Read .nvmrc
         run: echo "::set-output name=NVMRC::$(cat .nvmrc)"
diff --git a/.github/workflows/update-major-tag.yml b/.github/workflows/update-major-tag.yml
index c06cab8..91939f2 100644
--- a/.github/workflows/update-major-tag.yml
+++ b/.github/workflows/update-major-tag.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-18.04
     steps:
 
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
 
     - name: Update major tag
       if: github.event.release.prerelease == false