You hold: ♠ 98643 ♥ A4 ♦ KQ5 ♣ QJ3

Given your weak suit, you could double, but I lean toward overcalling one spade. How else will you find a 5-3 fit? Since you expect to be on lead against hearts most of the time if you lose the auction, you need not particularly fear partner leading a damaging spade. If you defend against no-trump, it could easily be best if partner leads a spade, since you seem to have the side entries for your partnership.