diff --git a/docs/parsers/whatwg-async-parser.md b/docs/parsers/whatwg-async-parser.md
index ffd795b..8e69e74 100644
--- a/docs/parsers/whatwg-async-parser.md
+++ b/docs/parsers/whatwg-async-parser.md
@@ -62,11 +62,6 @@ const csv = await parser.parse(data).promise();
 // The parse method return the stream transform readable side.
 // So data can be passed to a writable stream (a file, http request, etc.)
 parser.parse(data).pipeTo(writableStream);
-
-// You can also listen for events on the conversion and see how the header or the lines are coming out.
-parser
-  .addEventListener('header', (header) => console.log(header))
-  .addEventListener('line', (line) => console.log(line));
 ```
 
 ### Parameters
diff --git a/packages/whatwg/README.md b/packages/whatwg/README.md
index dc6e2af..50a91c2 100644
--- a/packages/whatwg/README.md
+++ b/packages/whatwg/README.md
@@ -172,13 +172,13 @@ To facilitate usage, `WHATWGAsyncParser` wraps `WHATWGTransformStream` exposing
 ### Usage
 
 ```js
-import { TransformStream } from '@json2csv/whatwg';
+import { AsyncParser } from '@json2csv/whatwg';
 
 const opts = {};
 const asyncOpts = {};
 const writableStrategy = {};
 const readableStrategy = {};
-const parser = new TransformStream(opts, asyncOpts, writableStrategy, readableStrategy);
+const parser = new AsyncParser(opts, asyncOpts, writableStrategy, readableStrategy);
 
 const response = await fetch('./my-file.json');
 
@@ -187,11 +187,6 @@ await response.body.pipeThrough(parser).pipeTo(writableStream);
 // The parse method return the stream transform readable side.
 // So data can be passed to a writable stream (a file, http request, etc.)
 parser.parse(data).pipeTo(writableStream);
-
-// You can also listen for events on the conversion and see how the header or the lines are coming out.
-parser
-  .addEventListener('header', (header) => console.log(header))
-  .addEventListener('line', (line) => console.log(line));
 ```
 
 #### Parameters
diff --git a/packages/whatwg/src/AsyncParser.ts b/packages/whatwg/src/AsyncParser.ts
index b05c147..61a28b4 100644
--- a/packages/whatwg/src/AsyncParser.ts
+++ b/packages/whatwg/src/AsyncParser.ts
@@ -1,5 +1,7 @@
 import type { ParserOptions, StreamParserOptions } from '@json2csv/plainjs';
-import JSON2CSVWHATWGTransformStream from './TransformStream.js';
+import JSON2CSVWHATWGTransformStream, {
+  type AwaitableReadableStream,
+} from './TransformStream.js';
 
 export default class JSON2CSVNodeAsyncParser<
   TRaw extends object,
@@ -36,7 +38,7 @@ export default class JSON2CSVNodeAsyncParser<
       | AsyncIterable<TRaw>
       | TRaw
       | ReadableStream<TRaw>,
-  ) {
+  ): AwaitableReadableStream<string> {
     if (typeof data === 'string' || ArrayBuffer.isView(data)) {
       data = new ReadableStream({
         start(controller) {
@@ -76,6 +78,6 @@ export default class JSON2CSVNodeAsyncParser<
       this.writableStrategy,
       this.readableStrategy,
     );
-    return data.pipeThrough(transform);
+    return data.pipeThrough(transform) as AwaitableReadableStream<string>;
   }
 }
diff --git a/packages/whatwg/src/TransformStream.ts b/packages/whatwg/src/TransformStream.ts
index c9e15b0..811fe37 100644
--- a/packages/whatwg/src/TransformStream.ts
+++ b/packages/whatwg/src/TransformStream.ts
@@ -42,7 +42,7 @@ class JSON2CSVWHATWGTransformer<TRaw extends object, T extends object>
   }
 }
 
-interface AwaitableReadableStream<T> extends ReadableStream<T> {
+export interface AwaitableReadableStream<T> extends ReadableStream<T> {
   promise(): Promise<string>;
 }
 
diff --git a/packages/whatwg/src/index.ts b/packages/whatwg/src/index.ts
index bd64449..b700aae 100644
--- a/packages/whatwg/src/index.ts
+++ b/packages/whatwg/src/index.ts
@@ -1,3 +1,6 @@
 export type { ParserOptions, StreamParserOptions } from '@json2csv/plainjs';
 export { default as AsyncParser } from './AsyncParser.js';
-export { default as TransformStream } from './TransformStream.js';
+export {
+  default as TransformStream,
+  type AwaitableReadableStream,
+} from './TransformStream.js';
diff --git a/packages/whatwg/test/AsyncParser.ts b/packages/whatwg/test/AsyncParser.ts
index 41ce180..12672cc 100644
--- a/packages/whatwg/test/AsyncParser.ts
+++ b/packages/whatwg/test/AsyncParser.ts
@@ -23,11 +23,11 @@ async function parseInput<TRaw extends object, T extends object>(
     | ReadableStream<TRaw>
     | Readable,
 ): Promise<string> {
-  return (
-    (await parser.parse(
+  return parser
+    .parse(
       nodeStream instanceof Readable ? Readable.toWeb(nodeStream) : nodeStream,
-    )) as any
-  ).promise();
+    )
+    .promise();
 }
 
 export default function (
diff --git a/packages/whatwg/test/AsyncParserInMemory.ts b/packages/whatwg/test/AsyncParserInMemory.ts
index 41ce180..12672cc 100644
--- a/packages/whatwg/test/AsyncParserInMemory.ts
+++ b/packages/whatwg/test/AsyncParserInMemory.ts
@@ -23,11 +23,11 @@ async function parseInput<TRaw extends object, T extends object>(
     | ReadableStream<TRaw>
     | Readable,
 ): Promise<string> {
-  return (
-    (await parser.parse(
+  return parser
+    .parse(
       nodeStream instanceof Readable ? Readable.toWeb(nodeStream) : nodeStream,
-    )) as any
-  ).promise();
+    )
+    .promise();
 }
 
 export default function (