diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index abe9cbc..419b719 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,6 +17,8 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v4
+      with:
+        ref: ${{ github.event.pull_request.head.sha }}
 
     - name: Install Nim
       uses: iffy/install-nim@v4