diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 4fc8849..5aca5df 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -79,7 +79,7 @@ jobs:
   phan:
     runs-on: ubuntu-22.04
     env:
-      branch: REL1_39
+      branch: REL1_43
     steps:
       - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2