diff --git a/packet.go b/packet.go
index 26a087e..2796a09 100644
--- a/packet.go
+++ b/packet.go
@@ -482,7 +482,7 @@ func (p Packet) Marshal() (buf []byte, err error) {
 }
 
 // MarshalTo serializes the packet and writes to the buffer.
-func (p Packet) MarshalTo(buf []byte) (n int, err error) {
+func (p *Packet) MarshalTo(buf []byte) (n int, err error) {
 	p.Header.Padding = p.PaddingSize != 0
 	n, err = p.Header.MarshalTo(buf)
 	if err != nil {