diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4349e3d..6afebde 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -21,9 +21,9 @@ jobs:
             "pactflow-example-provider-java-graphql",
           ]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
       - name: Set up JDK 17
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@c5195efecf7bdfc987ee8bae7a71cb8b11521c00 # v4
         with:
           distribution: 'zulu' 
           java-version: '17'
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: test
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
       - run: docker pull pactfoundation/pact-cli:latest
       - name: Can I deploy?
         run: GIT_BRANCH=${GIT_REF:11} make can_i_deploy
@@ -51,7 +51,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: can-i-deploy
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
       - run: docker pull pactfoundation/pact-cli:latest
       - name: Deploy
         run: GIT_BRANCH=${GIT_REF:11} make deploy