diff --git a/packages/captcha/src/TextStream.test.ts b/packages/captcha/src/TextStream.test.ts
new file mode 100644
index 0000000..47af137
--- /dev/null
+++ b/packages/captcha/src/TextStream.test.ts
@@ -0,0 +1,27 @@
+import { TextStream } from './TextStream'
+
+describe('TextStream', () => {
+
+  it('creates a text stream', async () => {
+    const stream = new TextStream('test')
+    const data = await new Promise((resolve, reject) => {
+      let text = ''
+      stream.on('error', reject)
+      stream.on('data', data => {
+        text += data.toString()
+      })
+      stream.on('end', () => {
+        resolve(text)
+      })
+    })
+    expect(data).toBe('test')
+  })
+
+  describe('_read', () => {
+    it('does nothing', () => {
+      const stream = new TextStream('test')
+      expect(stream._read()).toBe(undefined)
+    })
+  })
+
+})
diff --git a/packages/captcha/src/TextStream.ts b/packages/captcha/src/TextStream.ts
new file mode 100644
index 0000000..d0c03e1
--- /dev/null
+++ b/packages/captcha/src/TextStream.ts
@@ -0,0 +1,11 @@
+import { Readable } from 'stream'
+
+export class TextStream extends Readable {
+  constructor(text: string) {
+    super()
+    this.push(text)
+    this.push(null)
+  }
+  _read() {/* noop */}
+}
+
diff --git a/packages/captcha/src/audio.ts b/packages/captcha/src/audio.ts
index 3ebef65..dc641de 100644
--- a/packages/captcha/src/audio.ts
+++ b/packages/captcha/src/audio.ts
@@ -1,7 +1,7 @@
 import { Request, Response } from 'express'
-import { Readable } from 'stream'
-import { run, ReadableProcess, ReadableWritable, Command } from './run'
 import SVGCaptcha from 'svg-captcha'
+import { Command, ReadableProcess, ReadableWritable, run } from './run'
+import { TextStream } from './TextStream'
 
 export interface AudioConfig {
   commands: Command[]
@@ -44,15 +44,6 @@ export async function speak(
   return last
 }
 
-class TextStream extends Readable {
-  constructor(text: string) {
-    super()
-    this.push(text)
-    this.push(null)
-  }
-  _read() {/* noop */}
-}
-
 function createTextStream(text: string): ReadableProcess {
   return {
     stdout: new TextStream(text),