diff --git a/src/controllers/well-known/nostr.ts b/src/controllers/well-known/nostr.ts
index b1b84336..ae248954 100644
--- a/src/controllers/well-known/nostr.ts
+++ b/src/controllers/well-known/nostr.ts
@@ -4,7 +4,7 @@ import { z } from '@/deps.ts';
 import type { AppController } from '@/app.ts';
 import { Conf } from '../../config.ts';
 
-const nameSchema = z.string().min(1).regex(/^[\w_]+$/);
+const nameSchema = z.string().min(1).regex(/^\w+$/);
 
 /**
  * Serves NIP-05's nostr.json.
diff --git a/src/db.ts b/src/db.ts
index bff1190f..5f13af7b 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -4,7 +4,7 @@ const kv = await Deno.openKv();
 
 const userSchema = z.object({
   pubkey: z.string().regex(/^[0-9a-f]{64}$/).describe('primary'),
-  username: z.string().regex(/^[\w_]{1,30}$/).describe('unique'),
+  username: z.string().regex(/^\w{1,30}$/).describe('unique'),
   createdAt: z.date(),
 });