diff --git a/.github/workflows/quality.yml b/.github/workflows/quality.yml
index f218ab5..5feda5d 100644
--- a/.github/workflows/quality.yml
+++ b/.github/workflows/quality.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Projektstruktur prüfen
         run: |
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 27963af..1d9cb63 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Extract version from tag
         id: version
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index 5106a2c..7dd650b 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v3
@@ -36,7 +36,7 @@ jobs:
     if: github.event_name == 'pull_request'
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Dependency Review
         uses: actions/dependency-review-action@v4