Updating WordPress core and plugins is an important and often recurring maintenance task, that many often neglect due to the inherent risk of regressions and potential downtime. At Seravo.com we update hundreds of enterprise grade WordPress sites in a production-proof way using automated testing with RSpec and Phantom.js. In this talk I will show you how we do it and what are the open source tools anybody else can use as well to test their own sites before and after updates.