Klitschko unified the WBO and IBF titles against Sultan Ibragimov in February
Double world heavyweight champion Wladimir Klitschko will defend his WBO belt against American Tony Thompson in Hamburg on 12 July.
Thompson has 31 wins (19 KOs) and one defeat and is the WBO's number one challenger in the heavyweight division.
Klitschko requires IBF board clearance for the Thompson fight as Alexander Povetkin is their official challenger.
Ukrainian Klitschko, 32, unified the WBO and IBF titles when he beat Sultan Ibragimov in February in New York.
Klitschko has 50 professional wins with 44 KOs and three defeats.
The summer bout will to take place in the Color Line Arena in Hamburg.