diff --git a/.gitea/workflows/claude.yml b/.gitea/workflows/claude.yml
index bfa5dcc..6254097 100644
--- a/.gitea/workflows/claude.yml
+++ b/.gitea/workflows/claude.yml
@@ -6,13 +6,18 @@ on:
   issue_comment:
     types: [created]
 
+concurrency:
+  group: claude-${{ github.event.issue.number }}
+  cancel-in-progress: true
+
 jobs:
   claude-code:
     if: >-
       (github.event_name == 'issues' &&
        contains(toJSON(github.event.issue.labels), 'claude')) ||
       (github.event_name == 'issue_comment' &&
-       contains(github.event.comment.body, '@claude'))
+       contains(github.event.comment.body, '@claude') &&
+       github.event.comment.user.login != 'admin')
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps: