Somerset's overseas signing Alviro Petersen has agreed to extend his stay to feature in their Twenty20 campaign.
The South Africa opening batsman, who scored a century in the opening Test match against New Zealand last week, initially signed for the first half of the Championship season.
The 32-year-old will now stay until the end of July.
"I am very pleased that I will now be able to stay on at Somerset and play in the Twenty20 competition," he said.
"Over the years they have done well in the competition and I would like to think that my contributions will help them to lift the trophy."
Head coach Andy Hurry said: "This is great news for Somerset and having a top-class performer like Alviro in our T20 squad will certainly boost our batting and bring a wealth of experience to the side."
Port Elizabeth-born Petersen has featured in 20 Tests for his country, as well as 17 one-day internationals and two T20 internationals.
He has County Championship experience with Essex and Glamorgan.