Amazon.com, Inc. (NASDAQ:AMZN) announced a new delivery patent for devices with new features that would allow them to interact with humans and make adjustments in real time.

The U.S. Patent and Trademark Office has granted the e-commerce retailer a new patent for a delivery drone that can respond to human gestures and voice commands. The idea is to have unmanned aerial vehicles capable of sending packages to customers in 30 minutes or less.

The new design of these Amazon drone delivery devices is to improve the relationship between these delivery bots and the humans they’re interacting with in order to reduce the number of accidents or dissatisfied customers with the technology.

Based on a person’s gestures, the drones can adjust its behavior, whether it be a human issuing a thumbs-up, shouting or waving their arms in displeasure. The technology would allow the Amazon drones to release the packages they carry, change their flight path to avoid crashing, ask humans a question or stop the delivery.

“The human recipient and/or the other humans can communicate with the vehicle using human gestures to aid the vehicle along its path to the delivery location,” Amazon’s patent reads.

The drones would come equipped with a series of sensors, such as a depth sensor and cameras to detect visible, infrared and ultraviolet lights. These sensors would allow the Amazon devices to recognize hand and body gestures, voices and movement.

AMZN stock fell more than 1.8% Friday.