West Ham will sign Craig Dawson permanently for £2million after a clause in his contract was triggered by his 15th Premier League start against Wolves on Monday.
Dawson initially joined on a season-long loan from Championship club Watford and has played a key part in the Hammers' unexpected push for a top-four finish.
The 30-year-old's new contract with West Ham will run until the summer of 2023.
In those 15 league starts, the club have won nine, drawn three and lost three.