Hearts have extended the contracts of Billy King, Gary Oliver and Robbie Buchanan ahead of next season's Scottish Premiership campaign.
King, 20, and Buchanan, 19, have signed on for two more years, while Oliver has added an extra 12 months to his deal.
Winger King made 33 appearances as Hearts won the Scottish Championship, scoring nine goals.
"He's got a big future at the club and I'm glad to get him tied up," said head coach Robbie Neilson.
Buchanan, who was voted the club's Under-20s player of the year, and Oliver, 19, had loan spells at Cowdenbeath and Stenhousemuir respectively, as well as making 18 top-team appearances between them.
Neilson told the official Hearts website: "I'm pleased to get Billy signed up. He's performed really well for us this year.
"Both Gary and Robbie went out on loan this season and did really well. We were desperate to get Gary back from Stenhousemuir and into the first-team squad and get him involved, and he's done really well towards the end of the season.
"Robbie performed well on loan at Cowdenbeath and I was really pleased with his performances.
"The two of them will be pushing for the first-team squad next season so it's great to get two bright, young talents signed up."
Meanwhile, midfielder Scott Robinson will leave the club when his contract expires at the end of the month.