tracker/http.go | 1 +

diff --git a/tracker/http.go b/tracker/http.go
index 328c08322ba8e6cb1ac5339fce3d01f0e9eb6533..caf0cff64d9fee2dffa446de5c9818fc730fd87e 100644
--- a/tracker/http.go
+++ b/tracker/http.go
@@ -70,6 +70,7 @@
 func setAnnounceParams(_url *url.URL, ar *AnnounceRequest, opts Announce) {
 	q := _url.Query()
 
+	q.Set("key", strconv.FormatInt(int64(ar.Key), 10))
 	q.Set("info_hash", string(ar.InfoHash[:]))
 	q.Set("peer_id", string(ar.PeerId[:]))
 	// AFAICT, port is mandatory, and there's no implied port key.