Leigh Griffiths has signed a one-year contract extension with Celtic, promising an "exciting time" under new manager Ange Postecoglou.
The news comes on the day the 30-year-old striker's latest three-year deal was due to expire and with speculation rife about his possible departure.
Griffiths had posted a social media image on Wednesday of him training on his own in a Scotland jersey.
"I wanted to be part of the club's future," he told Celtic's website.
"Celtic is a club I love and want to do all I can to play my part again in bringing success to our supporters."
Griffiths made only nine starts last season after being criticised by then manager Neil Lennon for his physical condition on his return to training after lockdown.
His lack of game time also ensured he missed out on the Scotland squad for this summer's Euro 2020 finals.
But he recently told BBC Scotland he felt he had put those problems behind him and was fit enough to earn a new contract and help Celtic back to the top of the Scottish Premiership after missing out on a 10th consecutive title last season.
"I'm looking forward to the season ahead and working with the new gaffer and the rest of the lads," he said. "I'll be doing everything I can to help us get back to where we all want to be."
Griffiths, previously of Livingston, Dundee and Hibernian, joined Celtic from Wolverhampton Wanderers in 2014 and has made 261 appearances for the Glasgow club, scoring 123 goals.
Postecoglou added: "I am really pleased to keep Leigh with us for another season at least.
"I have had very positive conversations with Leigh and he clearly understands my expectations and more importantly the club's."