metainfo/metainfo.go | 15 +++++++++++++++
 t.go                 |  4 ++--
 torrent.go           |  2 +-

diff --git a/metainfo/metainfo.go b/metainfo/metainfo.go
index decfc3a001aac6fa6ee53efcb4d0ff261a79d6fb..14ff8d0470ef5a0200fd238815570266a513bc86 100644
--- a/metainfo/metainfo.go
+++ b/metainfo/metainfo.go
@@ -78,3 +78,18 @@ 	m.DisplayName = displayName
 	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 ed810a5fd08d98d3d1f50babbc1063105d7c851e..e6d231ca70d3cbe3bbb29350c7927f4e0ada8a75 100644
--- a/t.go
+++ b/t.go
@@ -197,8 +197,8 @@ 	}
 	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 929e0bc6454d1956f2529614d4c17211ac74a3dc..d515bc95fb77ed25df1c25786e6238055c6fad09 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1354,7 +1354,7 @@ 		// initial check.
 		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)
 		}
 	}