diff --git a/smoke-tests/index.js b/smoke-tests/index.js
index 9235c8960a26a..5e2d5e071ae12 100644
--- a/smoke-tests/index.js
+++ b/smoke-tests/index.js
@@ -1,8 +1,9 @@
 const fs = require('fs')
 const { promisify } = require('util')
 const execAsync = promisify(require('child_process').exec)
-const { resolve } = require('path')
+const { join, resolve } = require('path')
 const t = require('tap')
+const rimraf = promisify(require('rimraf'))
 
 const normalizePath = path => path.replace(/[A-Z]:/, '').replace(/\\/g, '/')
 const cwd = normalizePath(process.cwd())
@@ -47,6 +48,43 @@ const exec = async cmd => {
 const readFile = filename =>
   String(fs.readFileSync(resolve(localPrefix, filename)))
 
+// this test must come first, its package.json will be destroyed and the one
+// created in the next test (npm init) will create a new one that must be
+// present for later tests
+t.test('npm install sends correct user-agent', async t => {
+  const pkgPath = join(localPrefix, 'package.json')
+  const pkgContent = JSON.stringify({
+    name: 'smoke-test-workspaces',
+    workspaces: ['packages/*'],
+  })
+  fs.writeFileSync(pkgPath, pkgContent, { encoding: 'utf8' })
+
+  const wsRoot = join(localPrefix, 'packages')
+  fs.mkdirSync(wsRoot)
+
+  const wsPath = join(wsRoot, 'foo')
+  fs.mkdirSync(wsPath)
+
+  const wsPkgPath = join(wsPath, 'package.json')
+  const wsContent = JSON.stringify({
+    name: 'foo',
+  })
+  fs.writeFileSync(wsPkgPath, wsContent, { encoding: 'utf8' })
+  t.teardown(async () => {
+    await rimraf(`${localPrefix}/*`)
+  })
+
+  const cmd = `${npmBin} install fail_reflect_user_agent`
+  await t.rejects(exec(cmd), {
+    stderr: /workspaces\/false/,
+  }, 'workspaces/false is present in output')
+
+  const wsCmd = `${npmBin} install fail_reflect_user_agent --workspaces`
+  await t.rejects(exec(wsCmd), {
+    stderr: /workspaces\/true/,
+  }, 'workspaces/true is present in output')
+})
+
 t.test('npm init', async t => {
   const cmd = `${npmBin} init -y`
   const cmdRes = await exec(cmd)
diff --git a/smoke-tests/server.js b/smoke-tests/server.js
index b864114af64a8..e0ac0c94eb5ab 100644
--- a/smoke-tests/server.js
+++ b/smoke-tests/server.js
@@ -1,5 +1,5 @@
 /* istanbul ignore file */
-const {join, dirname} = require('path')
+const {join, dirname, basename} = require('path')
 const {existsSync, readFileSync, writeFileSync} = require('fs')
 const PORT = 12345 + (+process.env.TAP_CHILD_ID || 0)
 const http = require('http')
@@ -150,6 +150,12 @@ const startServer = () => new Promise((res, rej) => {
     }
 
     const f = join(__dirname, 'content', join('/', req.url.replace(/@/, '').replace(/%2f/i, '/')))
+    // a magic package that causes us to return an error that will be logged
+    if (basename(f) === 'fail_reflect_user_agent') {
+      res.setHeader('npm-notice', req.headers['user-agent'])
+      res.writeHead(404)
+      return res.end()
+    }
     const isCorgi = req.headers.accept.includes('application/vnd.npm.install-v1+json')
     const file = f + (
       isCorgi && existsSync(`${f}.min.json`) ? '.min.json'