Getting error Cannot read property 'viewport' of undefined in Puppeteer

I am trying to emulate devices on the puppeteer, for that I written below code block in nodejs and mocha test function

it('Should launch a mobile window', async function () {
    const mobile = puppeteer.devices['iPhone X']
    await page.emulate(mobile)
    await page.goto('https://www.imperva.com')
    await page.waitFor(5000)

})

But after running the test, I am getting below error

  1) Device emulation
   Should launch a mobile window:
 TypeError: Cannot read property 'viewport' of undefined
  at Page.emulate (node_modules\puppeteer\lib\cjs\puppeteer\common\Page.js:843:38)
  at Context.<anonymous> (tests\device.test.js:28:20)
  at processImmediate (internal/timers.js:456:21)

How to fix this issue?