The iPhone 11 series has been a success story for Apple so far, with launch demand being much better than many industry watchers expected. The iPhone 11’s slightly lower entry price compared to the iPhone XR must have helped boost demand, but the iPhone 11 Pro and iPhone 11 Pro Max have been the big success story of this iPhone generation so far.

We’ve seen several reports lauding Apple’s iPhone 11 sales performance, and the latest one comes from Korea, where Samsung Display has reportedly had to increase its OLED production iPhones. That’s proof that the more expensive Pro phones, which start at $999 or $1,099 depending on size, have been selling even better than Apple imagined.

Samsung is likely to supply up to 50 million OLED iPhone display units in the second half of the year, The Investor reports, citing a Money Today story that says the huge number is due to the “positive market response to the latest iPhone lineup.” That’s in stark contrast to the first quarter of the year, when Samsung delivered only 6 million OLED units to Apple, far below expectations. At the time, we heard the two parties were arguing over prices and Apple eventually ended up paying a penalty of $683 million for missing a sales target.

Samsung is still the leading supplier of OLED panels for the iPhone, with a 90% share according to the report. The iPhone’s OLED display is one of the costliest components of the phone, making Samsung’s deal with Apple a very lucrative one. Samsung is now expected to deliver almost 15 million OLED display units in October and November, with the total for the second half of the year set to hit anywhere between 40 million and 50 million, depending on the supply volume for December.

The report notes that Apple received almost 10 million OLED panels in September, a 40% increase compared to the initially planned 6.9 million units. That’s also an indication of early iPhone 11 Pro and 11 Pro Max success during the first month of availability. The iPhone 11 series launched in mid-September, hitting stores on the 20th.

Considering that Apple has discontinued the iPhone XS phones in September, all the OLED panels that Samsung is delivering to Apple will be used for iPhone 11 Pro and Pro Max production. That means Apple may be on track to sell up to 40 million iPhone 11 Pro units during the second half of the year. The iPhone maker no longer reports iPhone sales numbers in its quarterly earnings, but even if it did, it still wouldn’t share the actual split between LCD and OLED iPhones.

Samsung Display also supplies OLED panels for its own flagship phones, including the Galaxy S10 and Note 10, as well as other high-end handsets like Google’s Pixel. But none of these phones are likely to come anywhere close to matching Apple’s iPhone 11 Pro sales. The regular iPhone 11, meanwhile, features an LCD screen that’s mass-produced by either LG, Sharp, or Japan Display. The handset is also expected to sell very well in the first half of the year, although the report doesn’t offer any sales estimates.