diff --git a/common/buf/io.go b/common/buf/io.go
index 1a56bf75f..938e347bd 100644
--- a/common/buf/io.go
+++ b/common/buf/io.go
@@ -73,6 +73,17 @@ func NewReader(reader io.Reader) Reader {
 	}
 }
 
+// NewPacketReader creates a new PacketReader based on the given reader.
+func NewPacketReader(reader io.Reader) Reader {
+	if mr, ok := reader.(Reader); ok {
+		return mr
+	}
+
+	return &PacketReader{
+		Reader: reader,
+	}
+}
+
 func isPacketWriter(writer io.Writer) bool {
 	if _, ok := writer.(net.PacketConn); ok {
 		return true
diff --git a/proxy/dns/dns.go b/proxy/dns/dns.go
index 25ef76906..741f128f8 100644
--- a/proxy/dns/dns.go
+++ b/proxy/dns/dns.go
@@ -131,7 +131,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, d internet.
 		}
 	} else {
 		connReader = &dns_proto.UDPReader{
-			Reader: &buf.PacketReader{Reader: conn},
+			Reader: buf.NewPacketReader(conn),
 		}
 		connWriter = &dns_proto.UDPWriter{
 			Writer: buf.NewWriter(conn),
diff --git a/proxy/dokodemo/dokodemo.go b/proxy/dokodemo/dokodemo.go
index 350c0e179..d4302e39c 100644
--- a/proxy/dokodemo/dokodemo.go
+++ b/proxy/dokodemo/dokodemo.go
@@ -119,7 +119,7 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
 
 		var reader buf.Reader
 		if dest.Network == net.Network_UDP {
-			reader = &buf.PacketReader{Reader: conn}
+			reader = buf.NewPacketReader(conn)
 		} else {
 			reader = buf.NewReader(conn)
 		}
@@ -156,7 +156,7 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
 			defer tConn.Close()
 
 			writer = &buf.SequentialWriter{Writer: tConn}
-			tReader := &buf.PacketReader{Reader: tConn}
+			tReader := buf.NewPacketReader(tConn)
 			requestCount++
 			tproxyRequest = func() error {
 				defer func() {
diff --git a/proxy/freedom/freedom.go b/proxy/freedom/freedom.go
index ee21dd5a6..31397b543 100644
--- a/proxy/freedom/freedom.go
+++ b/proxy/freedom/freedom.go
@@ -166,7 +166,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		if destination.Network == net.Network_TCP {
 			reader = buf.NewReader(conn)
 		} else {
-			reader = &buf.PacketReader{Reader: conn}
+			reader = buf.NewPacketReader(conn)
 		}
 		if err := buf.Copy(reader, output, buf.UpdateActivity(timer)); err != nil {
 			return newError("failed to process response").Base(err)
diff --git a/proxy/shadowsocks/server.go b/proxy/shadowsocks/server.go
index cbafb0f94..14cee87a7 100644
--- a/proxy/shadowsocks/server.go
+++ b/proxy/shadowsocks/server.go
@@ -97,7 +97,7 @@ func (s *Server) handlerUDPPayload(ctx context.Context, conn internet.Connection
 	}
 	inbound.User = s.user
 
-	reader := &buf.PacketReader{Reader: conn}
+	reader := buf.NewPacketReader(conn)
 	for {
 		mpayload, err := reader.ReadMultiBuffer()
 		if err != nil {
diff --git a/proxy/socks/server.go b/proxy/socks/server.go
index de111b180..ae92b049c 100644
--- a/proxy/socks/server.go
+++ b/proxy/socks/server.go
@@ -200,7 +200,7 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn internet.Connection,
 		newError("client UDP connection from ", inbound.Source).WriteToLog(session.ExportIDToError(ctx))
 	}
 
-	reader := &buf.PacketReader{Reader: conn}
+	reader := buf.NewPacketReader(conn)
 	for {
 		mpayload, err := reader.ReadMultiBuffer()
 		if err != nil {