diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 44ce6de..b327b60 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -27,9 +27,9 @@ jobs:
             # 'pactflow-example-bi-directional-provider-dotnet'
           ]
     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'
@@ -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