diff --git a/.github/workflows/check-continentmap.yml b/.github/workflows/check-continentmap.yml
index 8c80e74..f2b116b 100644
--- a/.github/workflows/check-continentmap.yml
+++ b/.github/workflows/check-continentmap.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
 
     - name: Check continentmap
       run: make check-continentmap
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index f530fe0..2d69bc3 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
 
       - name: Install dependencies
         run: |
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bbd708d..8c2d8c4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -19,7 +19,7 @@ jobs:
           - "1.16"
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
     - uses: actions/setup-go@v2
       with:
         go-version: ${{ matrix.go-version }}