diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0ff94ce..0fcbc0e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
+    - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
 
     # Our tests require Nim to be installed to `/nim` because some error messages contain
     # e.g. `/nim/lib/pure/unittest.nim(654)`.
@@ -43,7 +43,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
+    - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
 
     - name: Download all `exercism/nim` exercises
       run: git clone --depth 1 https://github.com/exercism/nim.git
@@ -72,7 +72,7 @@ jobs:
         # Fail if the output JSON is not as expected.
         diff results.json expected_results.json
 
-    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
+    - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
       with:
         repository: 'ynfle/diff'
         ref: 'ae470e7702fd07a6ea850b2a6f2de701130fa048'
diff --git a/.github/workflows/lint_dockerfile.yml b/.github/workflows/lint_dockerfile.yml
index 1ffa460..70e7bb4 100644
--- a/.github/workflows/lint_dockerfile.yml
+++ b/.github/workflows/lint_dockerfile.yml
@@ -7,7 +7,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
 
       - name: Run hadolint
         uses: hadolint/hadolint-action@2332a7b74a6de0dda2e2221d575162eba76ba5e5
diff --git a/.github/workflows/shellcheck.yml b/.github/workflows/shellcheck.yml
index 12cb3bc..52ce404 100644
--- a/.github/workflows/shellcheck.yml
+++ b/.github/workflows/shellcheck.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
 
       - name: Run shellcheck
         uses: ludeeus/action-shellcheck@00cae500b08a931fb5698e11e79bfbd38e612a38