diff --git a/src/NWCClient.ts b/src/NWCClient.ts
index efa10b6..b324ce1 100644
--- a/src/NWCClient.ts
+++ b/src/NWCClient.ts
@@ -131,6 +131,7 @@ export type Nip47MakeInvoiceRequest = {
   description?: string;
   description_hash?: string;
   expiry?: number; // in seconds
+  metadata?: unknown;
 };
 
 export type Nip47LookupInvoiceRequest = {