diff --git a/.github/workflows/fr-coverage.yml b/.github/workflows/fr-coverage.yml
index b563395..9ca127c 100644
--- a/.github/workflows/fr-coverage.yml
+++ b/.github/workflows/fr-coverage.yml
@@ -5,5 +5,5 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - run: echo "FR coverage check placeholder"
diff --git a/.github/workflows/quality-gate.yml b/.github/workflows/quality-gate.yml
index aca0bf0..e7d2c63 100644
--- a/.github/workflows/quality-gate.yml
+++ b/.github/workflows/quality-gate.yml
@@ -5,5 +5,5 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - run: echo "Quality gate placeholder (phenotype-tooling integration pending)"