diff --git a/.github/workflows/ubuntu_action_test.yml b/.github/workflows/ubuntu_action_test.yml
index ea9adf2..591ec68 100644
--- a/.github/workflows/ubuntu_action_test.yml
+++ b/.github/workflows/ubuntu_action_test.yml
@@ -11,14 +11,14 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name != 'push'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - run: date > reports/ubuntu_report_minimal.txt
       - uses: https://w9r.dev/w9r.dev/action-git-commit-push@main
 
   ubuntu-full:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - run: date > reports/ubuntu_report_full.txt
       - uses: https://w9r.dev/w9r.dev/action-git-commit-push@main
         with:
@@ -36,5 +36,5 @@ jobs:
   ubuntu-nochanges:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - uses: GuillaumeFalourd/git-commit-push@main