diff --git a/.github/workflows/codecov.yml b/.github/workflows/codecov.yml
index 5d8f04a..b7acca7 100644
--- a/.github/workflows/codecov.yml
+++ b/.github/workflows/codecov.yml
@@ -8,7 +8,7 @@ jobs:
   codecov:
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
diff --git a/.github/workflows/mvn.yml b/.github/workflows/mvn.yml
index 5c61e1f..4d48e3a 100644
--- a/.github/workflows/mvn.yml
+++ b/.github/workflows/mvn.yml
@@ -15,7 +15,7 @@ jobs:
         os: [ubuntu-20.04, windows-2022, macos-12]
         java: [11, 17]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
diff --git a/.github/workflows/pdd.yml b/.github/workflows/pdd.yml
index 25f6357..353e914 100644
--- a/.github/workflows/pdd.yml
+++ b/.github/workflows/pdd.yml
@@ -11,5 +11,5 @@ jobs:
   pdd:
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: g4s8/pdd-action@master
diff --git a/.github/workflows/xcop.yml b/.github/workflows/xcop.yml
index 5682297..290ebfc 100644
--- a/.github/workflows/xcop.yml
+++ b/.github/workflows/xcop.yml
@@ -11,5 +11,5 @@ jobs:
   xcop:
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: g4s8/xcop-action@master