Philips Hue has a new accessory that’ll make it even easier to automate the lighting in your home: a motion sensor. This is, of course, a very standard add-on for home lighting — which is what makes its addition to the Hue lineup so important.

Hue hasn’t had any motion sensor options until now, so home owners who wanted to do motion sensing were either out of luck or stuck setting up a chain of third-party gadgets to get the same effect. This solves all of that.

The Hue motion sensor is a small white box with two AAA batteries inside that you’re supposed to place or mount in or around your house. It only detects motion — as in, it’s not a camera — and lets you automate lighting in response to whether people are or are not in a room.

Philips’ app makes it all pretty simple. It lets you pick out which lights to turn on when a motion sensor detects movement, as well as how long to keep them on for when it detects that everyone has left. There are a few nice touches here, too: lights will dim before turning off, so that a person can move again and trigger the motion sensor if it simply hasn’t picked up their presence in a while. And the motion sensor can be set to only activate lights when the room is dark, so that you aren’t wasting energy during the daytime.

The sensor does have some limits. It can only detect motion up to about 16.5 feet away. And while Philips will give you the option of reducing that — that is, only turning on lights when motion occurs closer to the sensor — you don’t have the option of limiting its sensitivity. That means your cat will end up triggering your lights, too. Philips says limits to motion sensitivity will come later on.

The motion sensors will sell for $39.95, with up to 12 supported on a single Hue bridge. They’ll go on sale in October.

Though Philips has added accessories to the Hue system in the past, such as switches, this is the first time it’s added something close to an additional gadget. Philips says it doesn’t plan to start expanding Hue into a broader smart home system, however. If it does add any other sensors in the future, they’ll be just as focused on improving home lighting.