Apple reportedly has a team of engineers working on new iPhone display technology in a secret laboratory in Longtan, Taiwan.

According to a report from Bloomberg, Apple has “at least 50 engineers” developing new screens based on both LED and OLED technology. The remote building is completely unmarked and said to be staffed primarily by workers from local display tech companies.

We’ve previously reported that Apple are planning to implement OLED (organic light-emitting diodes) displays within the next few years, most likely debuting in the iPhone 8. If true, it certainly lends credence to the idea that Apple is working under the radar on new displays.

OLED displays offer several benefits over Apple’s standard LED technology, and have already been adopted by many rival smartphone makers like Samsung. Developing displays in-house could lessen Apple’s reliance on other manufacturers, as well as providing some design and performance benefits: OLED screens offer better contrast and more saturated colors than LED, and are more power-efficient.

It’s possible Apple could develop the technology to an even higher standard by the time it’s ready to implement it in the iPhone. Apple has so far declined to comment.