diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 60036bd..3b4c08f 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -6,6 +6,12 @@ on:
   push:
     branches:
       - master
+ concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+     - master
 jobs:
   test:
     runs-on: ubuntu-latest