diff --git a/cmd/doozer/doozer.go b/cmd/doozer/doozer.go
index 3acb51f1..435fba54 100644
--- a/cmd/doozer/doozer.go
+++ b/cmd/doozer/doozer.go
@@ -73,7 +73,7 @@ func usage() {
 
 }
 
-func bail(e os.Error) {
+func bail(e error) {
 	fmt.Fprintln(os.Stderr, "Error:", e)
 	if e == doozer.ErrOldRev {
 		os.Exit(1)
diff --git a/cmd/doozer/find.go b/cmd/doozer/find.go
index 1c24c5ff..53241ef1 100644
--- a/cmd/doozer/find.go
+++ b/cmd/doozer/find.go
@@ -6,7 +6,6 @@ import (
 	"os"
 )
 
-
 func init() {
 	cmds["find"] = cmd{find, "<path>", "list files"}
 	cmdHelp["find"] = `Prints the tree rooted at <path>
@@ -15,12 +14,11 @@ Prints the path for each file or directory, one per line.
 `
 }
 
-
 func find(path string) {
 	c := dial()
 
 	if *rrev == -1 {
-		var err os.Error
+		var err error
 		*rrev, err = c.Rev()
 		if err != nil {
 			bail(err)
@@ -28,7 +26,7 @@ func find(path string) {
 	}
 
 	v := make(vis)
-	errs := make(chan os.Error)
+	errs := make(chan error)
 	go func() {
 		doozer.Walk(c, *rrev, path, v, errs)
 		close(v)
@@ -47,7 +45,6 @@ func find(path string) {
 	}
 }
 
-
 type vis chan string
 
 func (v vis) VisitDir(path string, f *doozer.FileInfo) bool {
diff --git a/cmd/doozer/wait.go b/cmd/doozer/wait.go
index 59ae8271..66046000 100644
--- a/cmd/doozer/wait.go
+++ b/cmd/doozer/wait.go
@@ -5,7 +5,6 @@ import (
 	"os"
 )
 
-
 func init() {
 	cmds["wait"] = cmd{wait, "<glob>", "wait for a change"}
 	cmdHelp["wait"] = `Prints the next change to a file matching <glob>.
@@ -27,12 +26,11 @@ bytes in the body, and LF is an ASCII line-feed char.
 `
 }
 
-
 func wait(path string) {
 	c := dial()
 
 	if *rrev == -1 {
-		var err os.Error
+		var err error
 		*rrev, err = c.Rev()
 		if err != nil {
 			bail(err)
diff --git a/cmd/doozer/watch.go b/cmd/doozer/watch.go
index 7f2b217c..f67d3234 100644
--- a/cmd/doozer/watch.go
+++ b/cmd/doozer/watch.go
@@ -5,7 +5,6 @@ import (
 	"os"
 )
 
-
 func init() {
 	cmds["watch"] = cmd{watch, "<glob>", "watch for a change"}
 	cmdHelp["watch"] = `Prints changes to any file matching <glob>.
@@ -27,12 +26,11 @@ Here, <path> is the file's path, <rev> is the revision of the change,
 `
 }
 
-
 func watch(glob string) {
 	c := dial()
 
 	if *rrev == -1 {
-		var err os.Error
+		var err error
 		*rrev, err = c.Rev()
 		if err != nil {
 			bail(err)
diff --git a/conn.go b/conn.go
index 1bb77a4c..64c569db 100644
--- a/conn.go
+++ b/conn.go
@@ -2,16 +2,16 @@ package doozer
 
 import (
 	"encoding/binary"
+	"errors"
 	"github.com/kr/pretty.go"
 	"goprotobuf.googlecode.com/hg/proto"
 
 	"io"
 	"log"
+	"math/rand"
 	"net"
-	"os"
-	"rand"
+	"net/url"
 	"strings"
-	"url"
 )
 
 var (
@@ -19,13 +19,13 @@ var (
 )
 
 var (
-	ErrInvalidUri = os.NewError("invalid uri")
+	ErrInvalidUri = errors.New("invalid uri")
 )
 
 type txn struct {
 	req  request
 	resp *response
-	err  os.Error
+	err  error
 	done chan bool
 }
 
@@ -34,15 +34,15 @@ type Conn struct {
 	conn    net.Conn
 	send    chan *txn
 	msg     chan []byte
-	err     os.Error
+	err     error
 	stop    chan bool
 	stopped chan bool
 }
 
 // Dial connects to a single doozer server.
-func Dial(addr string) (*Conn, os.Error) {
+func Dial(addr string) (*Conn, error) {
 	var c Conn
-	var err os.Error
+	var err error
 	c.addr = addr
 	c.conn, err = net.Dial("tcp", addr)
 	if err != nil {
@@ -53,7 +53,7 @@ func Dial(addr string) (*Conn, os.Error) {
 	c.msg = make(chan []byte)
 	c.stop = make(chan bool, 1)
 	c.stopped = make(chan bool)
-	errch := make(chan os.Error, 1)
+	errch := make(chan error, 1)
 	go c.mux(errch)
 	go c.readAll(errch)
 	return &c, nil
@@ -62,7 +62,7 @@ func Dial(addr string) (*Conn, os.Error) {
 // DialUri connects to one of the doozer servers given in `uri`. If `uri`
 // contains a cluster name, it will lookup addrs to try in `buri`.  If `uri`
 // contains a  secret key, then DialUri will call `Access` with the secret.
-func DialUri(uri, buri string) (*Conn, os.Error) {
+func DialUri(uri, buri string) (*Conn, error) {
 	if !strings.HasPrefix(uri, uriPrefix) {
 		return nil, ErrInvalidUri
 	}
@@ -112,7 +112,7 @@ func DialUri(uri, buri string) (*Conn, os.Error) {
 }
 
 // Find possible addresses for cluster named name.
-func lookup(b *Conn, name string) (as []string, err os.Error) {
+func lookup(b *Conn, name string) (as []string, err error) {
 	rev, err := b.Rev()
 	if err != nil {
 		return nil, err
@@ -137,7 +137,7 @@ func lookup(b *Conn, name string) (as []string, err os.Error) {
 	return as, nil
 }
 
-func (c *Conn) call(t *txn) os.Error {
+func (c *Conn) call(t *txn) error {
 	t.done = make(chan bool)
 	select {
 	case <-c.stopped:
@@ -162,10 +162,10 @@ func (c *Conn) Close() {
 	}
 }
 
-func (c *Conn) mux(errch chan os.Error) {
+func (c *Conn) mux(errch chan error) {
 	txns := make(map[int32]*txn)
 	var n int32 // next tag
-	var err os.Error
+	var err error
 
 	for {
 		select {
@@ -211,7 +211,7 @@ func (c *Conn) mux(errch chan os.Error) {
 				continue
 			}
 
-			txns[*r.Tag] = nil, false
+			delete(txns, *r.Tag)
 			t.resp = &r
 			t.done <- true
 		case err = <-errch:
@@ -232,7 +232,7 @@ error:
 	close(c.stopped)
 }
 
-func (c *Conn) readAll(errch chan os.Error) {
+func (c *Conn) readAll(errch chan error) {
 	for {
 		buf, err := c.read()
 		if err != nil {
@@ -244,7 +244,7 @@ func (c *Conn) readAll(errch chan os.Error) {
 	}
 }
 
-func (c *Conn) read() ([]byte, os.Error) {
+func (c *Conn) read() ([]byte, error) {
 	var size int32
 	err := binary.Read(c.conn, binary.BigEndian, &size)
 	if err != nil {
@@ -260,7 +260,7 @@ func (c *Conn) read() ([]byte, os.Error) {
 	return buf, nil
 }
 
-func (c *Conn) write(buf []byte) os.Error {
+func (c *Conn) write(buf []byte) error {
 	err := binary.Write(c.conn, binary.BigEndian, int32(len(buf)))
 	if err != nil {
 		return err
@@ -271,7 +271,7 @@ func (c *Conn) write(buf []byte) os.Error {
 }
 
 // Attempts access to the store
-func (c *Conn) Access(token string) os.Error {
+func (c *Conn) Access(token string) error {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_ACCESS)
 	t.req.Value = []byte(token)
@@ -279,7 +279,7 @@ func (c *Conn) Access(token string) os.Error {
 }
 
 // Sets the contents of file to body, if it hasn't been modified since oldRev.
-func (c *Conn) Set(file string, oldRev int64, body []byte) (newRev int64, err os.Error) {
+func (c *Conn) Set(file string, oldRev int64, body []byte) (newRev int64, err error) {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_SET)
 	t.req.Path = &file
@@ -295,7 +295,7 @@ func (c *Conn) Set(file string, oldRev int64, body []byte) (newRev int64, err os
 }
 
 // Deletes file, if it hasn't been modified since rev.
-func (c *Conn) Del(file string, rev int64) os.Error {
+func (c *Conn) Del(file string, rev int64) error {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_DEL)
 	t.req.Path = &file
@@ -303,7 +303,7 @@ func (c *Conn) Del(file string, rev int64) os.Error {
 	return c.call(&t)
 }
 
-func (c *Conn) Nop() os.Error {
+func (c *Conn) Nop() error {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_NOP)
 	return c.call(&t)
@@ -312,7 +312,7 @@ func (c *Conn) Nop() os.Error {
 // Returns the body and revision of the file at path,
 // as of store revision *rev.
 // If rev is nil, uses the current state.
-func (c *Conn) Get(file string, rev *int64) ([]byte, int64, os.Error) {
+func (c *Conn) Get(file string, rev *int64) ([]byte, int64, error) {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_GET)
 	t.req.Path = &file
@@ -329,7 +329,7 @@ func (c *Conn) Get(file string, rev *int64) ([]byte, int64, os.Error) {
 // Getdir reads up to lim names from dir, at revision rev, into an array.
 // Names are read in lexicographical order, starting at position off.
 // A negative lim means to read until the end.
-func (c *Conn) Getdir(dir string, rev int64, off, lim int) (names []string, err os.Error) {
+func (c *Conn) Getdir(dir string, rev int64, off, lim int) (names []string, err error) {
 	for lim != 0 {
 		var t txn
 		t.req.Verb = newRequest_Verb(request_GETDIR)
@@ -355,7 +355,7 @@ func (c *Conn) Getdir(dir string, rev int64, off, lim int) (names []string, err
 // Files are read in lexicographical order, starting at position off.
 // A negative lim means to read until the end.
 // Getdirinfo returns the array and an error, if any.
-func (c *Conn) Getdirinfo(dir string, rev int64, off, lim int) (a []FileInfo, err os.Error) {
+func (c *Conn) Getdirinfo(dir string, rev int64, off, lim int) (a []FileInfo, err error) {
 	names, err := c.Getdir(dir, rev, off, lim)
 	if err != nil {
 		return nil, err
@@ -380,7 +380,7 @@ func (c *Conn) Getdirinfo(dir string, rev int64, off, lim int) (a []FileInfo, er
 // Statinfo returns metadata about the file or directory at path,
 // in revision *storeRev. If storeRev is nil, uses the current
 // revision.
-func (c *Conn) Statinfo(rev int64, path string) (f *FileInfo, err os.Error) {
+func (c *Conn) Statinfo(rev int64, path string) (f *FileInfo, err error) {
 	f = new(FileInfo)
 	f.Len, f.Rev, err = c.Stat(path, &rev)
 	if err != nil {
@@ -398,7 +398,7 @@ func (c *Conn) Statinfo(rev int64, path string) (f *FileInfo, err os.Error) {
 // Stat returns metadata about the file or directory at path,
 // in revision *storeRev. If storeRev is nil, uses the current
 // revision.
-func (c *Conn) Stat(path string, storeRev *int64) (len int, fileRev int64, err os.Error) {
+func (c *Conn) Stat(path string, storeRev *int64) (len int, fileRev int64, err error) {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_STAT)
 	t.req.Path = &path
@@ -416,7 +416,7 @@ func (c *Conn) Stat(path string, storeRev *int64) (len int, fileRev int64, err o
 // Entries are read in lexicographical order, starting at position off.
 // A negative lim means to read until the end.
 // Conn.Walk will be removed in a future release. Use Walk instead.
-func (c *Conn) Walk(glob string, rev int64, off, lim int) (info []Event, err os.Error) {
+func (c *Conn) Walk(glob string, rev int64, off, lim int) (info []Event, err error) {
 	for lim != 0 {
 		var t txn
 		t.req.Verb = newRequest_Verb(request_WALK)
@@ -443,7 +443,7 @@ func (c *Conn) Walk(glob string, rev int64, off, lim int) (info []Event, err os.
 }
 
 // Waits for the first change, on or after rev, to any file matching glob.
-func (c *Conn) Wait(glob string, rev int64) (ev Event, err os.Error) {
+func (c *Conn) Wait(glob string, rev int64) (ev Event, err error) {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_WAIT)
 	t.req.Path = &glob
@@ -462,7 +462,7 @@ func (c *Conn) Wait(glob string, rev int64) (ev Event, err os.Error) {
 }
 
 // Rev returns the current revision of the store.
-func (c *Conn) Rev() (int64, os.Error) {
+func (c *Conn) Rev() (int64, error) {
 	var t txn
 	t.req.Verb = newRequest_Verb(request_REV)
 
diff --git a/err.go b/err.go
index bbecd6e8..60f95da2 100644
--- a/err.go
+++ b/err.go
@@ -1,17 +1,16 @@
 package doozer
 
 import (
+	"errors"
 	"goprotobuf.googlecode.com/hg/proto"
-	"os"
 )
 
 var (
-	ErrNoAddrs = os.NewError("no known address")
-	ErrBadTag  = os.NewError("bad tag")
-	ErrClosed  = os.NewError("closed")
+	ErrNoAddrs = errors.New("no known address")
+	ErrBadTag  = errors.New("bad tag")
+	ErrClosed  = errors.New("closed")
 )
 
-
 var (
 	ErrOther    response_Err = response_OTHER
 	ErrNotDir   response_Err = response_NOTDIR
@@ -23,13 +22,11 @@ var (
 	ErrReadonly response_Err = response_READONLY
 )
 
-
 type Error struct {
-	Err    os.Error
+	Err    error
 	Detail string
 }
 
-
 func newError(t *txn) *Error {
 	return &Error{
 		Err:    *t.resp.ErrCode,
@@ -37,9 +34,8 @@ func newError(t *txn) *Error {
 	}
 }
 
-
-func (e *Error) String() (s string) {
-	s = e.Err.String()
+func (e *Error) Error() (s string) {
+	s = e.Err.Error()
 	if e.Detail != "" {
 		s += ": " + e.Detail
 	}
diff --git a/msg.pb.go b/msg.pb.go
index c2c77caa..878f4832 100644
--- a/msg.pb.go
+++ b/msg.pb.go
@@ -5,12 +5,11 @@ package doozer
 
 import proto "goprotobuf.googlecode.com/hg/proto"
 import "math"
-import "os"
 
 // Reference proto, math & os imports to suppress error if they are not otherwise used.
 var _ = proto.GetString
 var _ = math.Inf
-var _ os.Error
+var _ error
 
 type request_Verb int32
 
@@ -110,7 +109,7 @@ func newResponse_Err(x response_Err) *response_Err {
 	e := response_Err(x)
 	return &e
 }
-func (x response_Err) String() string {
+func (x response_Err) Error() string {
 	return proto.EnumName(response_Err_name, int32(x))
 }
 
diff --git a/walk.go b/walk.go
index 13512ad4..52053726 100644
--- a/walk.go
+++ b/walk.go
@@ -1,18 +1,13 @@
 package doozer
 
-import (
-	"os"
-)
-
 type Visitor interface {
 	VisitDir(path string, f *FileInfo) bool
 	VisitFile(path string, f *FileInfo)
 }
 
-
 // Walk walks the file tree in revision rev, rooted at root,
 // analogously to Walk in package path/filepath.
-func Walk(c *Conn, rev int64, root string, v Visitor, errors chan<- os.Error) {
+func Walk(c *Conn, rev int64, root string, v Visitor, errors chan<- error) {
 	f, err := c.Statinfo(rev, root)
 	if err != nil {
 		if errors != nil {
@@ -23,8 +18,7 @@ func Walk(c *Conn, rev int64, root string, v Visitor, errors chan<- os.Error) {
 	walk(c, rev, root, f, v, errors)
 }
 
-
-func walk(c *Conn, r int64, path string, f *FileInfo, v Visitor, errors chan<- os.Error) {
+func walk(c *Conn, r int64, path string, f *FileInfo, v Visitor, errors chan<- error) {
 	if !f.IsDir {
 		v.VisitFile(path, f)
 		return