diff --git a/wrapper/test/output-listener.test.js b/wrapper/test/output-listener.test.js
index c7106e4..538c3e1 100644
--- a/wrapper/test/output-listener.test.js
+++ b/wrapper/test/output-listener.test.js
@@ -6,12 +6,16 @@
 const OutputListener = require('../lib/output-listener');
 const { PassThrough } = require('stream');
 describe('output-listener', () => {
-  it('receives and exposes data', () => {  
-    const listener = new OutputListener(new PassThrough());
+  it('receives and exposes data', () => {
+    const stream = new PassThrough();
+    const listener = new OutputListener(stream);
     const listen = listener.listener;
     listen(Buffer.from('foo'));
+    expect(stream.read()).toEqual(Buffer.from('foo'));
     listen(Buffer.from('bar'));
+    expect(stream.read()).toEqual(Buffer.from('bar'));
     listen(Buffer.from('baz'));
+    expect(stream.read()).toEqual(Buffer.from('baz'));
     expect(listener.contents).toEqual('foobarbaz');
   });
 });