diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e69b3331b3..64813934fe 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,6 +23,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
+          ref: ${{ github.event.pull_request.head.sha }}
           submodules: recursive
 
       - name: Use Java ${{ matrix.java }}