South Sydney have locked in young stars Cameron Murray and Campbell Graham until the end of the 2021 NRL season.
Both previously signed until the end of 2019, the move from the Rabbitohs takes the pair off the open market and ensures no rivals can attempt to lure them away from Redfern.
In their first full years of first grade, both players broke through onto the big stage regularly in Souths' run to the 2018 finals.
Murray, aged 20, made a name for himself off the bench in the semi-final win over St George Illawarra while 19-year-old Graham scored six tries in 16 games on the wing.
"Both Cameron and Campbell have shown they have what it takes to become regular NRL players and also to perform at the highest representative levels of the game in time," South Sydney football manager Shane Richardson said.
"Cameron is a workhorse and has made an impact on our team from the moment he was selected in first grade.
"Campbell is still eligible for the under 20s but his efforts in the NRL have seen him earn a spot in our back line over the past 18 months.
"He can play centre and has played wing already at NRL level and we're all excited to see what he can achieve."