diff --git a/dashboard/src/lib/api.ts b/dashboard/src/lib/api.ts
index edbb67bc..5e3bf3a0 100644
--- a/dashboard/src/lib/api.ts
+++ b/dashboard/src/lib/api.ts
@@ -49,8 +49,8 @@ export interface UserProfile {
   user_id: string;
   profile_content?: string;
   topics?: Record<string, any>;
-  created_at: string;
-  updated_at: string;
+  created_at?: string;
+  updated_at?: string;
 }
 
 export interface UserProfileListResponse {
diff --git a/dashboard/src/routes/user-profile.tsx b/dashboard/src/routes/user-profile.tsx
index 3a4f57ae..1b32cb93 100644
--- a/dashboard/src/routes/user-profile.tsx
+++ b/dashboard/src/routes/user-profile.tsx
@@ -119,7 +119,8 @@ function UserProfilePage() {
     return topicKeys.slice(0, 3).join(", ") + (topicKeys.length > 3 ? "..." : "");
   };
 
-  const formatDate = (dateString: string) => {
+  const formatDate = (dateString: string | undefined) => {
+    if (!dateString) return nullDisplay;
     try {
       return new Date(dateString).toLocaleString();
     } catch {