diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e3e8a81d..90b10c1a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,6 +26,10 @@ defaults:
   run:
     shell: bash
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
 jobs:
   tidy:
     uses: taiki-e/workflows/.github/workflows/tidy.yml@main