diff --git a/metainfo/metainfo.go b/metainfo/metainfo.go
index decfc3a0..14ff8d04 100644
--- a/metainfo/metainfo.go
+++ b/metainfo/metainfo.go
@@ -78,3 +78,18 @@ func (mi *MetaInfo) Magnet(displayName string, infoHash Hash) (m Magnet) {
 	m.InfoHash = infoHash
 	return
 }
+
+func (mi *MetaInfo) FlatTrackers() (ret []string) {
+	m := make(map[string]struct{})
+	for _, t := range mi.AnnounceList {
+		for _, s := range t {
+			m[s] = struct{}{}
+		}
+	}
+	m[mi.Announce] = struct{}{}
+	ret = make([]string, 0, len(m))
+	for s := range m {
+		ret = append(ret, s)
+	}
+	return
+}
diff --git a/t.go b/t.go
index ed810a5f..e6d231ca 100644
--- a/t.go
+++ b/t.go
@@ -197,8 +197,8 @@ func (t *Torrent) String() string {
 	return s
 }
 
-func (t *Torrent) AddTrackers(announceList [][]string) {
+func (t *Torrent) AddTrackers(urls []string) {
 	t.cl.mu.Lock()
 	defer t.cl.mu.Unlock()
-	t.addTrackers(announceList)
+	t.addTrackers([][]string{urls})
 }
diff --git a/torrent.go b/torrent.go
index 929e0bc6..d515bc95 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1354,7 +1354,7 @@ func (t *Torrent) pieceHashed(piece int, correct bool) {
 		if correct {
 			pieceHashedCorrect.Add(1)
 		} else {
-			log.Printf("%s: piece %d (%x) failed hash: %d connections contributed", t, piece, p.Hash, len(touchers))
+			log.Printf("%s: piece %d (%v) failed hash: %d connections contributed", t, piece, p.Hash, len(touchers))
 			pieceHashedNotCorrect.Add(1)
 		}
 	}