diff --git a/.github/workflows/build-protocol.yml b/.github/workflows/build-protocol.yml
index 8a883ed7..2e507bfc 100644
--- a/.github/workflows/build-protocol.yml
+++ b/.github/workflows/build-protocol.yml
@@ -31,6 +31,7 @@ jobs:
       - uses: actions/checkout@v3
         with:
           submodules: true
+          ref: ${{ github.event.pull_request.head.ref }}
 
       - uses: actions/setup-python@v4