diff --git a/.github/workflows/check_pr_source.yml b/.github/workflows/check_pr_source.yml
index b0ead9c8..877ab85c 100644
--- a/.github/workflows/check_pr_source.yml
+++ b/.github/workflows/check_pr_source.yml
@@ -3,7 +3,7 @@ name: Enforce test-staging → main
 on:
   pull_request:
     branches:
-      - main
+      - master
 
 jobs:
   require-test-staging: