diff --git a/.github/workflows/diff.yaml b/.github/workflows/diff.yaml
index dd31484a6..c82bd9278 100644
--- a/.github/workflows/diff.yaml
+++ b/.github/workflows/diff.yaml
@@ -1,6 +1,6 @@
 name: Diff
 concurrency:
-  group: ${{ github.head_ref }}
+  group: ${{ github.head_ref || github.sha }}
   cancel-in-progress: true
 
 on: