diff --git a/.github/workflows/pull_request.yml b/.github/workflows/pull_request.yml
index 1ea695d874e..d515b8ff561 100644
--- a/.github/workflows/pull_request.yml
+++ b/.github/workflows/pull_request.yml
@@ -12,6 +12,7 @@ jobs:
   check-format:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v2
       - uses: wolletd/clang-format-checker@v1.10
         with:
           target-ref: main