text: The Dons made an offer for the former St Johnstone forward, 24, in June but the deal was delayed after a managerial change at the Championship club.
  May, who has one Scotland cap to his name, was given his Saints debut as a 16-year-old by Dons boss Derek McInnes.
  "The manager has made no secret about trying to get me in the past, which is flattering," said May.
  "It's good to finally get the deal done which I think is right for both parties and I just can't wait to get started."
  May make close to 80 appearances for St Johnstone, enjoying loan spells at Alloa Athletic and Hamilton Academical, before moving to Sheffield Wednesday in August 2014 and on to Preston in January 2015.
  But he has been restricted to just 13 outings in the last two seasons, scoring just one goal.
  "I'm obviously delighted to get Stevie on board and he's a player I've enjoyed working with in the past and have been keen to work with again," said McInnes.
  "To get a 24-year-old international player on a four-year deal is a great piece of business by the club and I'd like to thank the board for their assistance in making it happen."
  May will go straight into the squad for Saturday's Premiership visit to Ross County, subject to clearance.
  Find all the latest football transfers on our dedicated page.
target: Aberdeen have completed the signing of Preston North End striker Stevie May on a four-year deal.