diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 061c87a76a..f78d257bf0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,9 +40,16 @@ jobs:
           toolchain: nightly
           override: true
       - name: Checkout
+        if: github.event_name != 'pull_request'
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      - name: Checkout
+        if: github.event_name == 'pull_request'
+        uses: actions/checkout@v2
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 0
       - name: Run tests
         run: |
           export CARGO_INCREMENTAL=0