CBS’ award-winning comedy Two and a Half Men will come to an end after a long run of 12 seasons this Thursday evening, and while he was only on the sitcom for its last three seasons, Ashton Kutcher is having a hard time saying goodbye to his co-star Jon Cryer. The 37-year-old actor posted a tribute to his 49-year-old costar on Twitter on Wednesday, and thanked his “very talented” friend for making his experience on the show so amazing.

After Two and a Half Men‘s original star Charlie Sheen was dismissed from the sitcom in 2011, Kutcher debuted as Walden Schmidt, a billionaire best friend and future husband to Cryer’s Alan Harper. Kutcher shared a picture of himself with Cryer to Twitter on Wednesday, and captioned the snapshot, “A toast to my very talented costar. Thank you for making this job exceed every expectation I had for it.”

Kutcher continued his tribute to Cryer on Facebook later Wednesday night, and said a final farewell to both his co-star and the series.

“Thank you Mr. Cryer for making this job never feel like work. I will miss working with you every day. You are a true partner in every sense of the word,” wrote Kutcher. “In four years I never heard you complain and never heard you speak ill of another person even if they took advantage of your kindness and generosity. Your are a gentleman. You are a talent. You are someone I look up to. See you tomorrow night. “