diff --git a/.github/workflows/check-code-quality.yml b/.github/workflows/check-code-quality.yml
index 30187171..5260b449 100644
--- a/.github/workflows/check-code-quality.yml
+++ b/.github/workflows/check-code-quality.yml
@@ -27,7 +27,7 @@ jobs:
         python-version: ["3.11", "3.12", "3.13"]
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v7
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 146e6d71..04f7003b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,7 +35,7 @@ jobs:
       version: ${{ steps.version.outputs.version }}
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v7
@@ -78,7 +78,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v7
@@ -114,7 +114,7 @@ jobs:
       tag: ${{ steps.tag.outputs.tag }}
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Load built wheel file
         uses: actions/download-artifact@v7
diff --git a/.github/workflows/citations.yml b/.github/workflows/citations.yml
index 2fedc663..7970bc4e 100644
--- a/.github/workflows/citations.yml
+++ b/.github/workflows/citations.yml
@@ -30,7 +30,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - name: checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Validate CITATION.cff
       uses: dieghernan/cff-validator@v4
diff --git a/.github/workflows/reuse-compliance.yml b/.github/workflows/reuse-compliance.yml
index e5b28a97..ae08f187 100644
--- a/.github/workflows/reuse-compliance.yml
+++ b/.github/workflows/reuse-compliance.yml
@@ -18,6 +18,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: REUSE Compliance Check
       uses: fsfe/reuse-action@v6
diff --git a/.github/workflows/sonar.yml b/.github/workflows/sonar.yml
index 74427b1e..d2df5205 100644
--- a/.github/workflows/sonar.yml
+++ b/.github/workflows/sonar.yml
@@ -23,7 +23,7 @@ jobs:
     steps:
 
       - name: Checkout source code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v7