diff --git a/.github/workflows/close-master-pr.yml b/.github/workflows/close-master-pr.yml
index 4ea39bb2de..a3d1695d8a 100644
--- a/.github/workflows/close-master-pr.yml
+++ b/.github/workflows/close-master-pr.yml
@@ -1,7 +1,8 @@
 name: Close PRs on master
 
 on:
-  workflow_dispatch:
+  pull_request_target:
+    types: [ opened, ready_for_review ]
 
 jobs:
   run: