t.go | 5 ++++-

diff --git a/t.go b/t.go
index d8ab0a7f93f089e791ce3bd1033a31263552c330..548247f762fa763e95d641be5941257caceaa4be 100644
--- a/t.go
+++ b/t.go
@@ -80,7 +80,10 @@ 	t.cl.dropTorrent(t.infoHash)
 	t.cl.mu.Unlock()
 }
 
-// Number of bytes of the entire torrent we have completed.
+// Number of bytes of the entire torrent we have completed. This is the sum of
+// completed pieces, and dirtied chunks of incomplete pieces. Do not use this
+// for download rate, as it can go down when pieces are lost or fail checks.
+// Sample Torrent.Stats.DataBytesRead for actual file data download rate.
 func (t *Torrent) BytesCompleted() int64 {
 	t.cl.mu.RLock()
 	defer t.cl.mu.RUnlock()