diff --git a/frontend/src/app/command/auctions/page.tsx b/frontend/src/app/command/auctions/page.tsx
index fbc16f8..807f9c8 100644
--- a/frontend/src/app/command/auctions/page.tsx
+++ b/frontend/src/app/command/auctions/page.tsx
@@ -203,7 +203,7 @@ export default function AuctionsPage() {
     setTrackingInProgress(domain)
     try {
       await api.addDomain(domain)
-      setTrackedDomains(prev => new Set([...prev, domain]))
+      setTrackedDomains(prev => new Set([...Array.from(prev), domain]))
     } catch (error) {
       console.error('Failed to track domain:', error)
     } finally {