diff --git a/.github/workflows/php-tests.yml b/.github/workflows/php-tests.yml
index 8ac7c50d..c7566084 100644
--- a/.github/workflows/php-tests.yml
+++ b/.github/workflows/php-tests.yml
@@ -22,7 +22,7 @@ jobs:
             allowed_failure: false
           # Check latest WP with the highest supported PHP.
           - php: 'latest'
-            wp: 'trunk'
+            wp: 'master'
             allowed_failure: false
 
     steps: