diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 52819ac..6c8f18b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -27,8 +27,8 @@ jobs:
             # 'pactflow-example-bi-directional-provider-dotnet'
           ]
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: '3.11' 
           architecture: 'x64' 
@@ -47,7 +47,7 @@ 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=${GIT_REF:11} make can_i_deploy
@@ -57,7 +57,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: can-i-deploy
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - run: docker pull pactfoundation/pact-cli:latest
       - name: Deploy
         run: GIT_BRANCH=${GIT_REF:11} make deploy