diff --git a/lib/types/aux-user-types.js b/lib/types/aux-user-types.js
--- a/lib/types/aux-user-types.js
+++ b/lib/types/aux-user-types.js
@@ -2,7 +2,7 @@
 
 import type { FarcasterUser } from './identity-service-types';
 
-export type AuxUserInfo = { +fid: string };
+export type AuxUserInfo = { +fid: ?string };
 
 export type AuxUserInfos = { +[userID: string]: AuxUserInfo };