diff --git a/src/controllers/activity.controller.ts b/src/controllers/activity.controller.ts
index 16b742c..9bbdae3 100644
--- a/src/controllers/activity.controller.ts
+++ b/src/controllers/activity.controller.ts
@@ -135,7 +135,7 @@ export default class ActivityController extends BaseController {
       results.push({
         rank: start + i / 2 + 1,
         level: rankLevel(score),
-        nickname: user.twitterName || user.discordName || formatAddress(user.address),
+        nickname: user?.twitterName || user?.discordName || user?.address ? formatAddress(user.address) : 'unknown',
         score,
         // yesterday: yesterdayScore ? parseInt(yesterdayScore + '') : 0,
       })