diff --git a/.github/workflows/architecture-guardian.yml b/.github/workflows/architecture-guardian.yml
index fa7d098..6328143 100644
--- a/.github/workflows/architecture-guardian.yml
+++ b/.github/workflows/architecture-guardian.yml
@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/cga-attestation.yml b/.github/workflows/cga-attestation.yml
index e41d9ac..5b026c1 100644
--- a/.github/workflows/cga-attestation.yml
+++ b/.github/workflows/cga-attestation.yml
@@ -40,7 +40,7 @@ jobs:
   offline-key:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0   # full history needed for git_stats during indexing
 
@@ -118,7 +118,7 @@ jobs:
   keyless-oidc:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/dogfood.yml b/.github/workflows/dogfood.yml
index 883b370..0539e1d 100644
--- a/.github/workflows/dogfood.yml
+++ b/.github/workflows/dogfood.yml
@@ -28,7 +28,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 50  # enough for pr-prep churn analysis
 
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 06c3d55..4d82a82 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -28,7 +28,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:
@@ -219,7 +219,7 @@ jobs:
     needs: publish
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:
diff --git a/.github/workflows/roam-ci.yml b/.github/workflows/roam-ci.yml
index 1d7fe34..433a75c 100644
--- a/.github/workflows/roam-ci.yml
+++ b/.github/workflows/roam-ci.yml
@@ -36,7 +36,7 @@ jobs:
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0   # full history needed for git-stats and pr-risk tests
 
@@ -62,7 +62,7 @@ jobs:
   test-no-optional-deps:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -83,7 +83,7 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:
@@ -111,7 +111,7 @@ jobs:
   doc-hygiene:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0   # for the test that uses git ls-files
 
@@ -148,7 +148,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'pull_request'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0   # full history required for pr-risk and git analysis
 
diff --git a/.github/workflows/roam.yml b/.github/workflows/roam.yml
index 46e5801..a3a13da 100644
--- a/.github/workflows/roam.yml
+++ b/.github/workflows/roam.yml
@@ -27,7 +27,7 @@ jobs:
   analyze:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0  # Full history needed for pr-risk and git analysis