Worcestershire have offset the loss of Joe Clarke to Nottinghamshire by taking Riki Wessels from Trent Bridge on a three-year deal.
Wessels, 32, joined from Northamptonshire in 2011, and became the first and only cricketer to circumvent the ECB's eligibility rules via the use of an entrepreneurial visa.
"Leaving Nottinghamshire was a difficult decision to make," said Wessels.
"I've spent eight years at Trent Bridge and enjoyed being part of successful teams that challenged for trophies but now is the right time for me to make a change.
"Worcestershire will provide a new challenge and I'm really looking forward to starting another chapter of my career at a club that I have a lot of admiration for."
Although Worcestershire were relegated from Division One of the County Championship, they did pick up silverware in the shape of the Vitality Twenty20 Blast.
Worcestershire will provide a new challenge and I'm really looking forward to starting another chapter of my career at a club that I have a lot of admiration for.Rikki Wessels
Wessels' explosive batting was fundamental in Nottinghamshire's cup double in 2017, and he became the club's first centurion in Twenty20 cricket last year.
"We'd like to thank Riki for his contribution to the side over the many years he's spent here at Trent Bridge," he said.
"However, both parties feel that now is the right time for a change and for Riki to move on. We wish him luck for the future."
View all Cricket betting