diff --git a/index.js b/index.js
index 82a599a..d2f8334 100644
--- a/index.js
+++ b/index.js
@@ -30,14 +30,18 @@ function createThreadInterceptor (opts) {
 
       const port = roundRobin.next()
 
-      if (opts.headers) {
-        delete opts.headers.connection
-        delete opts.headers['transfer-encoding']
+      const headers = {
+        ...opts?.headers,
       }
 
+      delete headers.connection
+      delete headers['transfer-encoding']
+      headers.host = url.host
+
       const id = nextId()
       const newOpts = {
         ...opts,
+        headers,
       }
       delete newOpts.dispatcher
 
@@ -169,7 +173,7 @@ function wire (server, port, opts) {
           statusCode: res.statusCode,
         }
 
-        if (res.headers['content-length'].indexOf('application/json')) {
+        if (res.headers['content-type'].indexOf('application/json')) {
           // fast path because it's utf-8, use a string
           newRes.rawPayload = res.payload
         } else {
diff --git a/package.json b/package.json
index 8fc338f..8748f24 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "An Undici interceptor that routes requests over a worker thread",
   "main": "index.js",
   "scripts": {
-    "test": "eslint && borp --coverage"
+    "test": "eslint && borp --coverage --check-coverage"
   },
   "keywords": [
     "undici",
diff --git a/test/basic.test.js b/test/basic.test.js
index 4afb42f..f8c4fbe 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -1,13 +1,14 @@
 'use strict'
 
 const { test } = require('node:test')
-const { deepStrictEqual, strictEqual } = require('node:assert')
+const { deepStrictEqual, strictEqual, rejects } = require('node:assert')
 const { join } = require('path')
 const { Worker } = require('worker_threads')
 const { createThreadInterceptor } = require('../')
 const { Agent, request } = require('undici')
 const { once } = require('events')
 const { setTimeout: sleep } = require('timers/promises')
+const Fastify = require('fastify')
 
 test('basic', async (t) => {
   const worker = new Worker(join(__dirname, 'fixtures', 'worker1.js'))
@@ -113,3 +114,108 @@ test('two service in a mesh, one is terminated, then a message is sent', async (
     statusCode: 500,
   })
 })
+
+test('buffer', async (t) => {
+  const worker = new Worker(join(__dirname, 'fixtures', 'worker1.js'))
+  t.after(() => worker.terminate())
+
+  const interceptor = createThreadInterceptor({
+    domain: '.local',
+  })
+  interceptor.route('myserver', worker)
+
+  const agent = new Agent().compose(interceptor)
+
+  const { statusCode, body } = await request('http://myserver.local/buffer', {
+    dispatcher: agent,
+  })
+
+  strictEqual(statusCode, 200)
+  deepStrictEqual(Buffer.from(await body.arrayBuffer()), Buffer.from('hello'))
+})
+
+test('handle errors from inject', async (t) => {
+  const worker = new Worker(join(__dirname, 'fixtures', 'error.js'))
+  t.after(() => worker.terminate())
+
+  const interceptor = createThreadInterceptor({
+    domain: '.local',
+  })
+  interceptor.route('myserver', worker)
+
+  const agent = new Agent().compose(interceptor)
+
+  await rejects(request('http://myserver.local', {
+    dispatcher: agent,
+  }), new Error('kaboom'))
+})
+
+test('pass through with domain', async (t) => {
+  const app = Fastify()
+  app.get('/', async () => {
+    return { hello: 'world' }
+  })
+  await app.listen({ port: 0 })
+  t.after(() => app.close())
+
+  const interceptor = createThreadInterceptor({
+    domain: '.local',
+  })
+
+  const agent = new Agent().compose(interceptor)
+
+  const { statusCode, body } = await request(app.listeningOrigin, {
+    dispatcher: agent,
+  })
+
+  strictEqual(statusCode, 200)
+  deepStrictEqual(await body.json(), { hello: 'world' })
+})
+
+test('unwanted headers are removed', async (t) => {
+  const worker = new Worker(join(__dirname, 'fixtures', 'worker1.js'))
+  t.after(() => worker.terminate())
+
+  const interceptor = createThreadInterceptor({
+    domain: '.local',
+  })
+  interceptor.route('myserver', worker)
+
+  const agent = new Agent().compose(interceptor)
+
+  const { statusCode, body } = await request('http://myserver.local/echo-headers', {
+    headers: {
+      'x-foo': 'bar',
+      connection: 'keep-alive',
+      'transfer-encoding': 'chunked',
+    },
+    dispatcher: agent,
+  })
+
+  strictEqual(statusCode, 200)
+  deepStrictEqual(await body.json(), {
+    'user-agent': 'lightMyRequest',
+    host: 'myserver.local',
+    'x-foo': 'bar',
+  })
+})
+
+test('multiple headers', async (t) => {
+  const worker = new Worker(join(__dirname, 'fixtures', 'worker1.js'))
+  t.after(() => worker.terminate())
+
+  const interceptor = createThreadInterceptor({
+    domain: '.local',
+  })
+  interceptor.route('myserver', worker)
+
+  const agent = new Agent().compose(interceptor)
+
+  const { statusCode, body, headers } = await request('http://myserver.local/headers', {
+    dispatcher: agent,
+  })
+
+  strictEqual(statusCode, 200)
+  deepStrictEqual(headers['x-foo'], ['bar', 'baz'])
+  await body.json()
+})
diff --git a/test/fixtures/error.js b/test/fixtures/error.js
new file mode 100644
index 0000000..c017263
--- /dev/null
+++ b/test/fixtures/error.js
@@ -0,0 +1,8 @@
+'use strict'
+
+const { parentPort } = require('worker_threads')
+const { wire } = require('../../')
+
+wire(function (req, res) {
+  res.destroy(new Error('kaboom'))
+}, parentPort)
diff --git a/test/fixtures/worker1.js b/test/fixtures/worker1.js
index c019549..2bb8080 100644
--- a/test/fixtures/worker1.js
+++ b/test/fixtures/worker1.js
@@ -6,12 +6,26 @@ const { wire } = require('../../')
 
 const app = fastify()
 
-app.get('/', async (req, reply) => {
+app.get('/', (req, reply) => {
   reply.send({ hello: workerData?.message || 'world' })
 })
 
-app.get('/whoami', async (req, reply) => {
+app.get('/whoami', (req, reply) => {
   reply.send({ threadId })
 })
 
+app.get('/buffer', (req, reply) => {
+  reply.send(Buffer.from('hello'))
+})
+
+app.get('/echo-headers', (req, reply) => {
+  reply.send(req.headers)
+})
+
+app.get('/headers', (req, reply) => {
+  reply
+    .header('x-foo', ['bar', 'baz'])
+    .send({ hello: 'world' })
+})
+
 wire(app, parentPort)
diff --git a/test/round-robin.test.js b/test/round-robin.test.js
index 976a0a9..3fa1111 100644
--- a/test/round-robin.test.js
+++ b/test/round-robin.test.js
@@ -7,6 +7,7 @@ const { Worker } = require('worker_threads')
 const { createThreadInterceptor } = require('../')
 const { Agent, request } = require('undici')
 const { once } = require('events')
+const RoundRobin = require('../lib/roundrobin')
 
 test('round-robin .route with array', async (t) => {
   const worker1 = new Worker(join(__dirname, 'fixtures', 'worker1.js'), {
@@ -141,3 +142,8 @@ test('round-robin one worker exits, in flight request', async (t) => {
     dispatcher: agent,
   }))
 })
+
+test('RoundRobin remove unknown port', () => {
+  const rr = new RoundRobin()
+  rr.remove({})
+})