diff --git a/.github/workflows/pull_request.yml b/.github/workflows/pull_request.yml
index 13a366a930..2e383fa619 100644
--- a/.github/workflows/pull_request.yml
+++ b/.github/workflows/pull_request.yml
@@ -7,6 +7,7 @@ on:
   pull_request:
     branches:
       - master
+      - 18.x
 jobs:
   buildAndTest:
     runs-on: ubuntu-latest