diff --git a/src/messages/types.ts b/src/messages/types.ts
index 5c4baf2..467fd95 100644
--- a/src/messages/types.ts
+++ b/src/messages/types.ts
@@ -1,8 +1,10 @@
+import { MessageSigningProtocols } from 'src/request';
 import type { RequestOptions, RequestPayload } from '../types';
 
 export interface SignMessagePayload extends RequestPayload {
   address: string;
   message: string;
+  protocol?: MessageSigningProtocols;
 }
 
 export type SignMessageResponse = string;