diff --git a/.github/workflows/backward-compatibility-check.yml b/.github/workflows/backward-compatibility-check.yml
index cb6fd2d..da05309 100644
--- a/.github/workflows/backward-compatibility-check.yml
+++ b/.github/workflows/backward-compatibility-check.yml
@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v3
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/coding-standard.yml b/.github/workflows/coding-standard.yml
index 88db7ed..6361eaf 100644
--- a/.github/workflows/coding-standard.yml
+++ b/.github/workflows/coding-standard.yml
@@ -29,7 +29,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v3
+              uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.25.5"
diff --git a/.github/workflows/mutation-tests.yml b/.github/workflows/mutation-tests.yml
index ce58e88..da2710e 100644
--- a/.github/workflows/mutation-tests.yml
+++ b/.github/workflows/mutation-tests.yml
@@ -29,7 +29,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v3
+              uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.25.5"
diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index 1258f5a..e4262dc 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -29,7 +29,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v3
+              uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.25.5"
diff --git a/.github/workflows/psalm.yml b/.github/workflows/psalm.yml
index ba219cc..8798c32 100644
--- a/.github/workflows/psalm.yml
+++ b/.github/workflows/psalm.yml
@@ -29,7 +29,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v3
+              uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.25.5"
diff --git a/.github/workflows/release-on-milestone-closed-triggering-release-event.yml b/.github/workflows/release-on-milestone-closed-triggering-release-event.yml
index 9388753..d031c17 100644
--- a/.github/workflows/release-on-milestone-closed-triggering-release-event.yml
+++ b/.github/workflows/release-on-milestone-closed-triggering-release-event.yml
@@ -18,7 +18,7 @@ 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/unit.yml b/.github/workflows/unit.yml
index 10cb76b..31ef3d8 100644
--- a/.github/workflows/unit.yml
+++ b/.github/workflows/unit.yml
@@ -38,7 +38,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v3
+              uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.25.5"