London:Andy Murray admits he needs to improve his on-court attitude after branding himself immature.
The British number one was recently described as a "miserable git" by Tim Henman, who insisted Murray must address his temperament if he is to win Wimbledon.
The 21-year-old conceded he can often seem miserable on court, but the Scot is determined to improve that aspect of his game as he bids for a first Grand Slam at the French Open and then Wimbledon.
"I personally think that off the court I'm pretty happy and don't get too down about things," Murray said. "But on the court, for sure, I could be more bubbly, if that's what everybody thinks.
"I've watched matches of myself and sometimes I think the way I act on court is great, and at other times I don't like it. Sometimes I'm immature on court and that's not really acceptable.
"It needs to get better but this year it's definitely been much better than the last four or five months of last year. Hopefully I'll get there but I'm working on it."