diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 4a2a1e2..1b4bb86 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -21,7 +21,7 @@ jobs:
     name: Lock file freshness
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
         with:
           persist-credentials: false
 
@@ -88,7 +88,7 @@ jobs:
       # cannot silently swap the underlying action code on this CI runner.
       # When bumping, verify the new SHA via:
       #   gh api repos/actions/<name>/git/ref/tags/<vN> --jq '.object.sha'
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
 
       - name: Set up Python
         uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065  # v5
@@ -128,7 +128,7 @@ jobs:
     name: Typecheck (mypy)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
 
       - name: Set up Python
         uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065  # v5
@@ -156,7 +156,7 @@ jobs:
     name: Secret scan (gitleaks)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/update-lock.yml b/.github/workflows/update-lock.yml
index 074f9a9..aa8046f 100644
--- a/.github/workflows/update-lock.yml
+++ b/.github/workflows/update-lock.yml
@@ -17,7 +17,7 @@ jobs:
     name: Regenerate requirements-lock.txt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
         with:
           persist-credentials: false