diff --git a/.github/workflows/auto-milestone.yml b/.github/workflows/auto-milestone.yml
index ce931664283..dd66fc1c085 100644
--- a/.github/workflows/auto-milestone.yml
+++ b/.github/workflows/auto-milestone.yml
@@ -2,6 +2,7 @@ name: Auto-milestone
 on:
   pull_request:
     types:
+      - opened
       - closed
 
 jobs: