Porto have announced they have secured the services of Santos midfielder Danilo until the summer of 2016.
The Portuguese champions revealed last week they had come to an agreement with Santos for the €13 million transfer of the Brazil under-20 international, but made no mention of the contract's length.
A new statement issued by Porto to the Portuguese stock market (CMVM) reads that Danilo has signed a five-year contract, with a €50m release clause attached to the deal.
Danilo, who can play in the midfield and in the backline, was one of the most sought-after commodities in the transfer market in the summer, having also attracted interest from Benfica and AC Milan.
The Brazilian, who is currently away on international duty with Brazil's Under-20 squad at the World Cup, will only link up with Porto at the end of the year, when the Club World Cup has come to an end.