diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 449161d7f..fe1c4f8cc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,5 +1,11 @@
 name: Rust CI
 
+# Cancel previously started workflow runs
+# when the branch is updated.
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
+
 on:
   pull_request:
   push: