diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 774aeb8..1e98bad 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,9 +17,9 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - name: Set up JDK 17
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@3a4f6e1af504cf6a31855fa899c6aa5355ba6c12 # v4
         with:
           distribution: 'zulu' 
           java-version: '17'
@@ -31,7 +31,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: test
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - run: docker pull pactfoundation/pact-cli:latest
       - name: Can I deploy?
         run: GIT_BRANCH=${GITHUB_REF:11} make can_i_deploy
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: can-i-deploy
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - run: docker pull pactfoundation/pact-cli:latest
       - name: Deploy
         run: GIT_BRANCH=${GITHUB_REF:11} make deploy
diff --git a/.github/workflows/contract_requiring_verification_published.yml b/.github/workflows/contract_requiring_verification_published.yml
index ca97bf7..36b0335 100644
--- a/.github/workflows/contract_requiring_verification_published.yml
+++ b/.github/workflows/contract_requiring_verification_published.yml
@@ -28,15 +28,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout default branch if user manually provides pact URL
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
         if: ${{ github.event.inputs.PACT_URL }}
       - name: checkout specific SHA if webhook provides pact URL
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
         if: ${{ github.event.client_payload.pact_url }}
         with:
           ref: ${{env.GIT_COMMIT}}
       - name: Set up JDK 17
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@3a4f6e1af504cf6a31855fa899c6aa5355ba6c12 # v4
         with:
           distribution: 'zulu' 
           java-version: '17'