Google has an idea for keeping drones from crash landing while delivering toilet paper to your doorstep. That plan involves a big computerized lock box with wheels.

The search giant filed for a patent this week that involves its planned delivery drones dropping off orders inside individual wheeled lockboxes around town. In addition to holding on to the package, the system would guard against potential dangers like drones crashing into homes, hitting trees, and leaving orders on wet lawns.

Google’s patent application is notably different from Amazon’s planned rival drone delivery service, at least as shown in a recent Amazon commercial. In it, one of the e-commerce giant’s drones hovers above a backyard over a small pad that resembles an Amazon doormat. It then lands on the pad, drops off the package for the family to pick up, and flies away.

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However, Google’s patent filing envisions a more centralized system. Rather than going door-to-door, it delivers to a central and presumably secure hub.

The drone flies to a local delivery box that is equipped with infrared beacon transmitters that help guide the drone to close proximity. The drone would then place the package into the wheeled box, which would then automatically roll to a safe spot like a garage or warehouse that would hold onto the order until the intended recipient shows up. It’s also possible that the box could be outfitted with robotic legs, in which case it would walk to the warehouse and drop off the package using a robotic arm or conveyor belt.

Customers would receive a notification, presumably through a phone or other mobile device, that their package has arrived.

Although it may be more convenient for drones to drop off package at door steps and backyards, the Google filing explains that doing so may be risky. For example, the filing mentions that a drone with a propeller could be dangerous to pets or power lines nearby or that it may have trouble locating a safe landing zone.

Of course, it’s worth noting that just because Google filed a patent, doesn’t mean that this will become reality.

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In 2014, Amazon filed a similar patent application for its own drone delivery system roughly shown in its commercial. In its filing, the company described a the possibility of customers pressing a “Bring It To Me” button on a smartphone app so that the drone can easily find them using GPS and drop off their package.

Amazon’s filing explained that the drone would scan for animals or people that may be in its way so it can steer clear. Additionally, once the drone nears its destination, it would try to land in a safe area pick out with the help of some undescribed “remote entity controller,” which sounds like a fancy way of saying guidance software.