Ulster academy players Angus Curtis and Tom O'Toole have been rewarded with upgraded contracts by the province.
The pair, who both made their senior debuts last season, will remain on development deals this season before moving into the senior squad next year.
Tighthead prop O'Toole, 19, who made five appearances for Ulster last season will now stay at Kingspan Stadium until the summer of 2022.
Versatile back Curtis, 20, has signed up with his native province until 2021.
Ulster have also confirmed that Rory Best will continue as captain for the 2018-19 season.
The Ireland skipper, capped 111 times at international level, will miss Ulster's start to the season due to the hamstring injury which kept him out of Ireland's series win in Australia in June.
Curtis made his Pro14 debut against Glasgow in April and also featured in the draw against Munster at Thomond Park later that month.
"I have thoroughly enjoyed being part of the setup at Ulster and it's a big bonus for me to graduate from the Academy at this stage of the season," said Curtis, who can play at fly-half and centre.
"I've learnt a lot within the Academy programme and I'm looking forward to continuing to work hard with the senior squad. This group has massive potential and I'm looking forward to seeing what we can achieve together."
O'Toole made his Ulster debut in the victory against Edinburgh at Murrayfield and retained his place in the squad for the remainder of the campaign as Ulster finished the season with a five-game unbeaten run to clinch a place in the Heineken Champions Cup.
The Drogheda-native emigrated to Australia with his family as a boy but was persuaded to return to Ireland before the end of his schoolboy career.
"I'm really excited about the prospect of furthering my rugby career at Ulster, where I have enjoyed such a great experience to date," said O'Toole.
"The support from the Academy over the past few years has been incredible in developing all aspects of my game and preparing me to step up to the next level.
"I'm very grateful for this opportunity and am ready to give everything I can to the Ulster cause."
Ulster begin the new Pro14 season at home to Scarlets at Kingspan Stadium on Saturday, 1 September [17:15 BST].