diff --git a/index.d.ts b/index.d.ts
index f40b23f..c8c3cab 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -68,7 +68,7 @@ declare namespace Pikmin
 
     export class FileTransport implements Transport
     {
-        constructor(options: { file: string | PathLike, flags?: '-a' });
+        constructor(options: { file: string | PathLike, flags?: '-a', format: string });
 
         /** The type of the transport, implemented by the Transport interface */
         public type: 'CONSOLE' | 'WEBHOOK' | 'FILE';