diff --git a/tracker/udp-server_test.go b/tracker/udp-server_test.go
index b32fe853..7308ed0d 100644
--- a/tracker/udp-server_test.go
+++ b/tracker/udp-server_test.go
@@ -47,7 +47,7 @@ func (s *server) respond(addr net.Addr, rh udp.ResponseHeader, parts ...interfac
 }
 
 func (s *server) newConn() (ret udp.ConnectionId) {
-	ret = rand.Int63()
+	ret = rand.Uint64()
 	if s.conns == nil {
 		s.conns = make(map[udp.ConnectionId]struct{})
 	}
diff --git a/tracker/udp/protocol.go b/tracker/udp/protocol.go
index f6beb4c6..653d013e 100644
--- a/tracker/udp/protocol.go
+++ b/tracker/udp/protocol.go
@@ -26,7 +26,7 @@ const (
 
 type TransactionId = int32
 
-type ConnectionId = int64
+type ConnectionId = uint64
 
 type ConnectionRequest struct {
 	ConnectionId  ConnectionId
diff --git a/tracker/udp/server/server.go b/tracker/udp/server/server.go
index dfcc6500..20e827b9 100644
--- a/tracker/udp/server/server.go
+++ b/tracker/udp/server/server.go
@@ -181,7 +181,7 @@ func randomConnectionId() udp.ConnectionId {
 	if err != nil {
 		panic(err)
 	}
-	return int64(binary.BigEndian.Uint64(b[:]))
+	return binary.BigEndian.Uint64(b[:])
 }
 
 func RunSimple(ctx context.Context, s *Server, pc net.PacketConn, family udp.AddrFamily) error {