diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 02e17f7..ed27aa3 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -8,6 +8,11 @@ on:
   pull_request:
   workflow_dispatch:
 
+# Cancel an in-progress run when a newer commit supersedes it on the same ref.
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check:
     runs-on: arch