diff --git a/src/pkg/net/udpsock_plan9.go b/src/pkg/net/udpsock_plan9.go
index d5c6ccb..60dec81 100644
--- a/src/pkg/net/udpsock_plan9.go
+++ b/src/pkg/net/udpsock_plan9.go
@@ -7,6 +7,7 @@
 package net
 
 import (
+	"errors"
 	"os"
 )
 
@@ -24,7 +25,7 @@
 //
 // ReadFromUDP can be made to time out and return an error with Timeout() == true
 // after a fixed time limit; see SetTimeout and SetReadTimeout.
-func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err os.Error) {
+func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err error) {
 	if !c.ok() {
 		return 0, nil, os.EINVAL
 	}
@@ -40,7 +41,7 @@
 		return
 	}
 	if m < udpHeaderSize {
-		return 0, nil, os.NewError("short read reading UDP header")
+		return 0, nil, errors.New("short read reading UDP header")
 	}
 	buf = buf[:m]
 
@@ -50,7 +51,7 @@
 }
 
 // ReadFrom implements the net.PacketConn ReadFrom method.
-func (c *UDPConn) ReadFrom(b []byte) (n int, addr Addr, err os.Error) {
+func (c *UDPConn) ReadFrom(b []byte) (n int, addr Addr, err error) {
 	if !c.ok() {
 		return 0, nil, os.EINVAL
 	}
@@ -63,7 +64,7 @@
 // an error with Timeout() == true after a fixed time limit;
 // see SetTimeout and SetWriteTimeout.
 // On packet-oriented connections, write timeouts are rare.
-func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (n int, err os.Error) {
+func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (n int, err error) {
 	if !c.ok() {
 		return 0, os.EINVAL
 	}
@@ -87,7 +88,7 @@
 }
 
 // WriteTo implements the net.PacketConn WriteTo method.
-func (c *UDPConn) WriteTo(b []byte, addr Addr) (n int, err os.Error) {
+func (c *UDPConn) WriteTo(b []byte, addr Addr) (n int, err error) {
 	if !c.ok() {
 		return 0, os.EINVAL
 	}
@@ -101,7 +102,7 @@
 // DialUDP connects to the remote address raddr on the network net,
 // which must be "udp", "udp4", or "udp6".  If laddr is not nil, it is used
 // as the local address for the connection.
-func DialUDP(net string, laddr, raddr *UDPAddr) (c *UDPConn, err os.Error) {
+func DialUDP(net string, laddr, raddr *UDPAddr) (c *UDPConn, err error) {
 	switch net {
 	case "udp", "udp4", "udp6":
 	default:
@@ -149,7 +150,7 @@
 // local address laddr.  The returned connection c's ReadFrom
 // and WriteTo methods can be used to receive and send UDP
 // packets with per-packet addressing.
-func ListenUDP(net string, laddr *UDPAddr) (c *UDPConn, err os.Error) {
+func ListenUDP(net string, laddr *UDPAddr) (c *UDPConn, err error) {
 	switch net {
 	case "udp", "udp4", "udp6":
 	default:
@@ -172,7 +173,7 @@
 // JoinGroup joins the IP multicast group named by addr on ifi,
 // which specifies the interface to join.  JoinGroup uses the
 // default multicast interface if ifi is nil.
-func (c *UDPConn) JoinGroup(ifi *Interface, addr IP) os.Error {
+func (c *UDPConn) JoinGroup(ifi *Interface, addr IP) error {
 	if !c.ok() {
 		return os.EINVAL
 	}
@@ -180,7 +181,7 @@
 }
 
 // LeaveGroup exits the IP multicast group named by addr on ifi.
-func (c *UDPConn) LeaveGroup(ifi *Interface, addr IP) os.Error {
+func (c *UDPConn) LeaveGroup(ifi *Interface, addr IP) error {
 	if !c.ok() {
 		return os.EINVAL
 	}