torrent.go | 5 ++++-

diff --git a/torrent.go b/torrent.go
index d53efb0acb96ec75fe4ebc17b84e9b53cb755cd2..d0f81fd7f1bc3a2628ca5abd3616b0d486b74e1e 100644
--- a/torrent.go
+++ b/torrent.go
@@ -982,7 +982,10 @@ }
 
 func (t *Torrent) unpendPieces(unpend *bitmap.Bitmap) {
 	t.pendingPieces.Sub(unpend)
-	t.updatePiecePriorities()
+	unpend.IterTyped(func(piece int) (again bool) {
+		t.updatePiecePriority(piece)
+		return true
+	})
 }
 
 func (t *Torrent) pendPieceRange(begin, end int) {