Newcastle have re-signed rookie twins Daniel and Jacob Saifiti until the end of the 2018 NRL season.
The 20-year-old brothers made their debut together in the Knights' season-opening loss to Gold Coast, and have now played a combined 14 of a possible 18 games between them this year.
Knights coach Nathan Brown said it was crucial for the club to tie down the Fijian duo as the club continues its rebuilding phase.
"Daniel and Jacob have been in our system for some time now and we are delighted to secure them at the club long term," Brown said.
"They have both impressed this year and we know they will only continue to improve.
"They are a significant part of our plan at the Knights to build the team around our young local talent where possible.
"Not only are they talented young players, they are fine young men, which is equally as important in building our roster."
The pair have both been named to start in Sunday's clash against Cronulla.