diff --git a/nip05.ts b/nip05.ts
index 7a7b76e..6bd1cc5 100644
--- a/nip05.ts
+++ b/nip05.ts
@@ -7,7 +7,7 @@ import { ProfilePointer } from './nip19.ts'
  * - 1: name (optional)
  * - 2: domain
  */
-export const NIP05_REGEX = /^(?:([\w.+-]+)@)?([\w.-]+)$/
+export const NIP05_REGEX = /^(?:([\w.+-]+)@)?[\w_-]+(\.[\w_-]+)+$/
 
 var _fetch: any