Just as Slack reported quarterly earnings, it also announced a new agreement with Amazon. Under the terms of the deal Slack will keep using Amazon Web Services (AWS) as its preferred cloud provider — as it has since launching in 2014 — and is shifting its Slack Calls feature to use Amazon Chime.

In case you’ve forgotten what Amazon Chime is, it’s the in-house teleconferencing tool the company revealed a few years ago. However, an exec told CNBC in an interview that it hadn’t invested in creating a UI on the level of what Slack has, which is why in a world with Zoom, Skype and Google Meet you probably aren’t using it. Slack will rework its call technology to use Chime’s backend service, so that it can work reliably and add new features — like mobile video and automatic transcriptions — easily.