diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d1362f5..f4e2467 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
     name: shellcheck install + scripts
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install shellcheck
         run: sudo apt-get update -qq && sudo apt-get install -y shellcheck
       - name: Lint shell scripts
@@ -45,7 +45,7 @@ jobs:
     name: pyflakes + py_compile
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: '3.12'
@@ -66,7 +66,7 @@ jobs:
     name: pytest (no ROS env — import structure only)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: '3.12'
@@ -93,7 +93,7 @@ jobs:
     name: walkthrough HTML smoke (links, structure)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: '3.12'
@@ -121,7 +121,7 @@ jobs:
     name: markdown link sanity (relative paths only)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: '3.12'