diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index b0cde6a..b7294d9 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -11,7 +11,7 @@ jobs:
     name: phpstan
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index e29f22e..5646d4f 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -24,7 +24,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
diff --git a/.github/workflows/update-changelog.yml b/.github/workflows/update-changelog.yml
index 0cdea23..fa06fdf 100644
--- a/.github/workflows/update-changelog.yml
+++ b/.github/workflows/update-changelog.yml
@@ -10,7 +10,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           ref: main