Livingston boss David Martindale was delighted to sign long-term target James Penrice from Partick Thistle on a three-year-deal.
The 22-year-old defender played 13 times on-loan from the Jags in the 2017-18 season before being recalled by the Firhill side in January 2018.
Striker Scott Tiffoney moves the other way, re-joining Partick Thistle after a successful loan spell at the end of last season.
Martindale told the club's official website: "I'm very pleased to get the signing of James over the line – I've actually been trying to bring him back to the club for a number of years in all honesty.
"He did extremely well in his loan spell with us back in the 17/18 season and ever since then, I've kept a close eye on his development.
"James is a fantastic footballer with a great left foot and I see him as a player who can adapt to a few positions, predominantly on the left-hand side.
"He is a very good age and has played a lot of football for a young player with over 150 games to his name and only turns 23 in December, so he comes with good experience and previous knowledge of the club.
"Personally, I've known James and his family for many years and know he is a really good character.
"I'm delighted to be able to bring a local lad, who was involved in the Livingston FC academy many years ago, back to Livingston FC.
"He will sign a three-year agreement and wear the number 29 shirt next season.
"James will bring host of qualities to the first-team squad and I'm looking forward to working with him again.
"Scott Tiffoney will move to Partick Thistle as part of the transfer agreement. Tiff needed to get out and play 1st team football every week and he has shown while on loan at Partick that he can score goals.
"All in all, I think it's a very good bit of business for both clubs and most importantly, both players."
