diff --git a/types/index.d.ts b/types/index.d.ts
index f9f4e7c..96960a8 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -49,7 +49,7 @@ export interface IConnectPacket extends IPacket {
   password?: Buffer
   will?: {
     topic: string
-    payload: Buffer
+    payload: Buffer | string
     qos?: QoS
     retain?: boolean
     properties?: {