diff --git a/.github/workflows/pull-request.yml b/.github/workflows/pull-request.yml
index 252519eb..034bc9fb 100644
--- a/.github/workflows/pull-request.yml
+++ b/.github/workflows/pull-request.yml
@@ -5,6 +5,7 @@ on:
     branches:
       - main
       - 2201.[0-9]+.x
+      - update4
 
 jobs:
   ubuntu-build: