diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 582c515d..f12418ce 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -52,7 +52,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac" # v4
         with:
           fetch-depth: 0
 
@@ -104,7 +104,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac" # v4
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/release-on-milestone-closed.yml b/.github/workflows/release-on-milestone-closed.yml
index 388e50b5..a7cb27e0 100644
--- a/.github/workflows/release-on-milestone-closed.yml
+++ b/.github/workflows/release-on-milestone-closed.yml
@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac" # v4
 
       - name: "Release"
         uses: "laminas/automatic-releases@v1"
diff --git a/.github/workflows/release-phar.yml b/.github/workflows/release-phar.yml
index 9d8c46c1..9f98ef23 100644
--- a/.github/workflows/release-phar.yml
+++ b/.github/workflows/release-phar.yml
@@ -24,7 +24,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac" # v4
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@2.24.0"