diff --git a/.github/workflows/attack.yaml b/.github/workflows/attack.yaml
index 6329621..6d77abf 100644
--- a/.github/workflows/attack.yaml
+++ b/.github/workflows/attack.yaml
@@ -2,6 +2,8 @@ name: Attack!
 on:
   workflow_dispatch:
   pull_request:
+    branches:
+      - main
 
 jobs:
   check-coding-syle: