diff --git a/.github/workflows/ci-master.yml b/.github/workflows/ci-master.yml
index 3e04d44a..3c5a5795 100644
--- a/.github/workflows/ci-master.yml
+++ b/.github/workflows/ci-master.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       
diff --git a/.github/workflows/claude-code-review.yml b/.github/workflows/claude-code-review.yml
index a12225aa..1c3de8c0 100644
--- a/.github/workflows/claude-code-review.yml
+++ b/.github/workflows/claude-code-review.yml
@@ -27,7 +27,7 @@ jobs:
     
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 1
 
diff --git a/.github/workflows/claude.yml b/.github/workflows/claude.yml
index bc773072..1790d4fd 100644
--- a/.github/workflows/claude.yml
+++ b/.github/workflows/claude.yml
@@ -26,7 +26,7 @@ jobs:
       actions: read # Required for Claude to read CI results on PRs
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 1
 
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 05d80bc9..95684972 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       
@@ -73,7 +73,7 @@ jobs:
       fail-fast: false
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 9ab19610..b702dfd8 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
       
       - uses: actions/setup-python@v5
         with:
@@ -80,7 +80,7 @@ jobs:
     if: github.ref == 'refs/heads/master' && github.event_name == 'push'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
       
       - uses: actions/setup-python@v5
         with:
diff --git a/.github/workflows/doctest_validation.yml b/.github/workflows/doctest_validation.yml
index c98296c0..88e372bd 100644
--- a/.github/workflows/doctest_validation.yml
+++ b/.github/workflows/doctest_validation.yml
@@ -19,7 +19,7 @@ jobs:
       fail-fast: false  # Allow other jobs to complete even if one fails
     
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4
@@ -211,7 +211,7 @@ jobs:
       fail-fast: false
     
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index b4f632ba..f937fed5 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -24,7 +24,7 @@ jobs:
   build-and-publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0  # Need full history for setuptools_scm
       
@@ -194,7 +194,7 @@ jobs:
       !contains(github.ref, 'dev')
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index bb30df0f..744bb526 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -12,7 +12,7 @@ jobs:
   security:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
       
       - uses: actions/setup-python@v5
         with:
diff --git a/.github/workflows/sync-requirements.yml b/.github/workflows/sync-requirements.yml
index 6524b8ac..ad1bacd6 100644
--- a/.github/workflows/sync-requirements.yml
+++ b/.github/workflows/sync-requirements.yml
@@ -19,7 +19,7 @@ jobs:
   sync-requirements:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
         with:
           token: ${{ secrets.GITHUB_TOKEN }}