Tranmere defender Mark McChrystal has extended his contract at Prenton Park for a further two years.
The 27-year-old signed for Rovers in January from Derry City after impressing while on trial and played 23 times last season.
Tranmere manager Les Parry said: "He's a very calm defender who is strong in the air and a good communicator.
"Mark joined in January and instantly settled into the heart of the defence and put in some great displays."
"When we signed him in January we had the option of extending his deal by another 12 months," Parry continued. "On the back of his performances we very quickly decided that we wanted to extend our association for an even longer period."
McChrystal added: "I really like it at Tranmere and settled in quickly back in January so I'm happy to be staying for longer.
"The manager gave me a good opportunity when he brought me over from Derry and I'm glad to be able to repay him by extending my contract."