I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

Service worker does not start/install.

Expected behavior

Service worker should always start/install.

Minimal reproduction of the problem with instructions

• create new project
  ng new test-service-worker --service-worker
• add this code to the app.component's constructor:
  setInterval(function() { console.log('test'); }, 1000);
• build app
  ng build --prod
• service worker will never start/install

Environment

Angular version: 5.1.0
CLI: 1.6.0