Middlesbrough have signed Brentford striker Marcus Forss for an undisclosed fee on a four-year deal.
The 23-year-old Finland international scored eight goals in 54 league appearances for the Bees.
Forss could make his debut for Chris Wilder's side in Saturday's Championship opener against West Brom.
"He played a big part in Brentford winning promotion a couple of seasons ago, and he knows this league well," Wilder told the club website.
Former Baggies youngster Forss scored one goal in 11 appearances on loan at Hull in the second half of last season, though only five of those were starts.