diff --git a/internal/constants/constants.go b/internal/constants/constants.go
new file mode 100644
index 0000000..9db50c1
--- /dev/null
+++ b/internal/constants/constants.go
@@ -0,0 +1,54 @@
+// Copyright 2016 The go-libvirt Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package constants provides shared data for the libvirt package.
+package constants
+
+// magic program numbers
+// see: https://libvirt.org/git/?p=libvirt.git;a=blob_plain;f=src/remote/remote_protocol.x;hb=HEAD
+const (
+	ProgramVersion   = 1
+	ProgramRemote    = 0x20008086
+	ProgramQEMU      = 0x20008087
+	ProgramKeepAlive = 0x6b656570
+)
+
+// libvirt procedure identifiers
+const (
+	ProcConnectOpen           = 1
+	ProcConnectClose          = 2
+	ProcDomainLookupByName    = 23
+	ProcAuthList              = 66
+	ProcConnectGetLibVersion  = 157
+	ProcConnectListAllDomains = 273
+)
+
+// qemu procedure identifiers
+const (
+	QEMUDomainMonitor                       = 1
+	QEMUConnectDomainMonitorEventRegister   = 4
+	QEMUConnectDomainMonitorEventDeregister = 5
+	QEMUDomainMonitorEvent                  = 6
+)
+
+const (
+	// PacketLengthSize is the packet length, in bytes.
+	PacketLengthSize = 4
+
+	// HeaderSize is the packet header size, in bytes.
+	HeaderSize = 24
+
+	// UUIDSize is the length of a UUID, in bytes.
+	UUIDSize = 16
+)
diff --git a/libvirt.go b/libvirt.go
index ead2d71..34d9375 100644
--- a/libvirt.go
+++ b/libvirt.go
@@ -25,6 +25,7 @@ import (
 	"sync"
 
 	"github.com/davecgh/go-xdr/xdr2"
+	"github.com/digitalocean/go-libvirt/internal/constants"
 )
 
 // ErrEventsNotSupported is returned by Events() if event streams
@@ -52,7 +53,7 @@ type Libvirt struct {
 // Domain represents a domain as seen by libvirt.
 type Domain struct {
 	Name string
-	UUID [uuidSize]byte
+	UUID [constants.UUIDSize]byte
 	ID   int
 }
 
@@ -108,7 +109,7 @@ func (l *Libvirt) Domains() ([]Domain, error) {
 		return nil, err
 	}
 
-	resp, err := l.request(procConnectListAllDomains, programRemote, &buf)
+	resp, err := l.request(constants.ProcConnectListAllDomains, constants.ProgramRemote, &buf)
 	if err != nil {
 		return nil, err
 	}
@@ -159,7 +160,7 @@ func (l *Libvirt) Events(dom string) (<-chan DomainEvent, error) {
 		return nil, err
 	}
 
-	resp, err := l.request(qemuConnectDomainMonitorEventRegister, programQEMU, &buf)
+	resp, err := l.request(constants.QEMUConnectDomainMonitorEventRegister, constants.ProgramQEMU, &buf)
 	if err != nil {
 		return nil, err
 	}
@@ -218,7 +219,7 @@ func (l *Libvirt) Run(dom string, cmd []byte) ([]byte, error) {
 		return nil, err
 	}
 
-	resp, err := l.request(qemuDomainMonitor, programQEMU, &buf)
+	resp, err := l.request(constants.QEMUDomainMonitor, constants.ProgramQEMU, &buf)
 	if err != nil {
 		return nil, err
 	}
@@ -242,7 +243,7 @@ func (l *Libvirt) Run(dom string, cmd []byte) ([]byte, error) {
 
 // Version returns the version of the libvirt daemon.
 func (l *Libvirt) Version() (string, error) {
-	resp, err := l.request(procConnectGetLibVersion, programRemote, nil)
+	resp, err := l.request(constants.ProcConnectGetLibVersion, constants.ProgramRemote, nil)
 	if err != nil {
 		return "", err
 	}
@@ -286,7 +287,7 @@ func (l *Libvirt) lookup(name string) (*Domain, error) {
 		return nil, err
 	}
 
-	resp, err := l.request(procDomainLookupByName, programRemote, &buf)
+	resp, err := l.request(constants.ProcDomainLookupByName, constants.ProgramRemote, &buf)
 	if err != nil {
 		return nil, err
 	}
diff --git a/libvirt_test.go b/libvirt_test.go
index dbed492..8b987e0 100644
--- a/libvirt_test.go
+++ b/libvirt_test.go
@@ -19,10 +19,12 @@ import (
 	"fmt"
 	"testing"
 	"time"
+
+	"github.com/digitalocean/go-libvirt/libvirttest"
 )
 
 func TestConnect(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	err := l.Connect()
@@ -32,7 +34,7 @@ func TestConnect(t *testing.T) {
 }
 
 func TestDisconnect(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	err := l.Disconnect()
@@ -42,7 +44,7 @@ func TestDisconnect(t *testing.T) {
 }
 
 func TestDomains(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	domains, err := l.Domains()
@@ -70,7 +72,7 @@ func TestDomains(t *testing.T) {
 }
 
 func TestEvents(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 	done := make(chan struct{})
 
@@ -108,14 +110,14 @@ func TestEvents(t *testing.T) {
 	}()
 
 	// send an event to the listener goroutine
-	conn.test.Write(append(testEventHeader, testEvent...))
+	conn.Test.Write(append(testEventHeader, testEvent...))
 
 	// wait for completion
 	<-done
 }
 
 func TestRun(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	res, err := l.Run("test", []byte(`{"query-version"}`))
@@ -147,7 +149,7 @@ func TestRun(t *testing.T) {
 }
 
 func TestVersion(t *testing.T) {
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	version, err := l.Version()
diff --git a/mock_test.go b/libvirttest/libvirt.go
similarity index 84%
rename from mock_test.go
rename to libvirttest/libvirt.go
index e79707c..77e097c 100644
--- a/mock_test.go
+++ b/libvirttest/libvirt.go
@@ -12,12 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package libvirt
+// Package libvirttest provides a mock libvirt server for RPC testing.
+package libvirttest
 
 import (
 	"encoding/binary"
 	"net"
 	"sync/atomic"
+
+	"github.com/digitalocean/go-libvirt/internal/constants"
 )
 
 var testDomainResponse = []byte{
@@ -164,18 +167,20 @@ var testVersionReply = []byte{
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x4d, 0xfc, // version (1003004)
 }
 
-type mockLibvirt struct {
+// MockLibvirt provides a mock libvirt server for testing.
+type MockLibvirt struct {
 	net.Conn
-	test   net.Conn
+	Test   net.Conn
 	serial uint32
 }
 
-func setupTest() *mockLibvirt {
+// New creates a new mock Libvirt server.
+func New() *MockLibvirt {
 	serv, conn := net.Pipe()
 
-	m := &mockLibvirt{
+	m := &MockLibvirt{
 		Conn: conn,
-		test: serv,
+		Test: serv,
 	}
 
 	go m.handle(serv)
@@ -183,9 +188,10 @@ func setupTest() *mockLibvirt {
 	return m
 }
 
-func (m *mockLibvirt) handle(conn net.Conn) {
+func (m *MockLibvirt) handle(conn net.Conn) {
 	for {
-		buf := make([]byte, packetLengthSize+headerSize)
+		// packetLengthSize + headerSize
+		buf := make([]byte, 28)
 		conn.Read(buf)
 
 		// extract program
@@ -195,45 +201,45 @@ func (m *mockLibvirt) handle(conn net.Conn) {
 		proc := binary.BigEndian.Uint32(buf[12:16])
 
 		switch prog {
-		case programRemote:
+		case constants.ProgramRemote:
 			m.handleRemote(proc, conn)
-		case programQEMU:
+		case constants.ProgramQEMU:
 			m.handleQEMU(proc, conn)
 		}
 	}
 }
 
-func (m *mockLibvirt) handleRemote(procedure uint32, conn net.Conn) {
+func (m *MockLibvirt) handleRemote(procedure uint32, conn net.Conn) {
 	switch procedure {
-	case procAuthList:
+	case constants.ProcAuthList:
 		conn.Write(m.reply(testAuthReply))
-	case procConnectOpen:
+	case constants.ProcConnectOpen:
 		conn.Write(m.reply(testConnectReply))
-	case procConnectClose:
+	case constants.ProcConnectClose:
 		conn.Write(m.reply(testDisconnectReply))
-	case procConnectGetLibVersion:
+	case constants.ProcConnectGetLibVersion:
 		conn.Write(m.reply(testVersionReply))
-	case procDomainLookupByName:
+	case constants.ProcDomainLookupByName:
 		conn.Write(m.reply(testDomainResponse))
-	case procConnectListAllDomains:
+	case constants.ProcConnectListAllDomains:
 		conn.Write(m.reply(testDomainsReply))
 	}
 }
 
-func (m *mockLibvirt) handleQEMU(procedure uint32, conn net.Conn) {
+func (m *MockLibvirt) handleQEMU(procedure uint32, conn net.Conn) {
 	switch procedure {
-	case qemuConnectDomainMonitorEventRegister:
+	case constants.QEMUConnectDomainMonitorEventRegister:
 		conn.Write(m.reply(testRegisterEvent))
-	case qemuConnectDomainMonitorEventDeregister:
+	case constants.QEMUConnectDomainMonitorEventDeregister:
 		conn.Write(m.reply(testDeregisterEvent))
-	case qemuDomainMonitor:
+	case constants.QEMUDomainMonitor:
 		conn.Write(m.reply(testRunReply))
 	}
 }
 
 // reply automatically injects the correct serial
 // number into the provided response buffer.
-func (m *mockLibvirt) reply(buf []byte) []byte {
+func (m *MockLibvirt) reply(buf []byte) []byte {
 	atomic.AddUint32(&m.serial, 1)
 	binary.BigEndian.PutUint32(buf[20:24], m.serial)
 
diff --git a/rpc.go b/rpc.go
index b8f2121..c0c1c46 100644
--- a/rpc.go
+++ b/rpc.go
@@ -23,6 +23,7 @@ import (
 	"sync/atomic"
 
 	"github.com/davecgh/go-xdr/xdr2"
+	"github.com/digitalocean/go-libvirt/internal/constants"
 )
 
 // ErrUnsupported is returned if a procedure is not supported by libvirt
@@ -68,44 +69,6 @@ const (
 	StatusContinue
 )
 
-// magic program numbers
-// see: https://libvirt.org/git/?p=libvirt.git;a=blob_plain;f=src/remote/remote_protocol.x;hb=HEAD
-const (
-	programVersion   = 1
-	programRemote    = 0x20008086
-	programQEMU      = 0x20008087
-	programKeepAlive = 0x6b656570
-)
-
-// libvirt procedure identifiers
-const (
-	procConnectOpen           = 1
-	procConnectClose          = 2
-	procDomainLookupByName    = 23
-	procAuthList              = 66
-	procConnectGetLibVersion  = 157
-	procConnectListAllDomains = 273
-)
-
-// qemu procedure identifiers
-const (
-	qemuDomainMonitor                       = 1
-	qemuConnectDomainMonitorEventRegister   = 4
-	qemuConnectDomainMonitorEventDeregister = 5
-	qemuDomainMonitorEvent                  = 6
-)
-
-const (
-	// packet length, in bytes.
-	packetLengthSize = 4
-
-	// packet header, in bytes.
-	headerSize = 24
-
-	// UUID size, in bytes.
-	uuidSize = 16
-)
-
 // header is a libvirt rpc packet header
 type header struct {
 	// Program identifier
@@ -168,7 +131,7 @@ func (l *Libvirt) connect() error {
 
 	// libvirt requires that we call auth-list prior to connecting,
 	// event when no authentication is used.
-	resp, err := l.request(procAuthList, programRemote, &buf)
+	resp, err := l.request(constants.ProcAuthList, constants.ProgramRemote, &buf)
 	if err != nil {
 		return err
 	}
@@ -178,7 +141,7 @@ func (l *Libvirt) connect() error {
 		return decodeError(r.Payload)
 	}
 
-	resp, err = l.request(procConnectOpen, programRemote, &buf)
+	resp, err = l.request(constants.ProcConnectOpen, constants.ProgramRemote, &buf)
 	if err != nil {
 		return err
 	}
@@ -192,7 +155,7 @@ func (l *Libvirt) connect() error {
 }
 
 func (l *Libvirt) disconnect() error {
-	resp, err := l.request(procConnectClose, programRemote, nil)
+	resp, err := l.request(constants.ProcConnectClose, constants.ProgramRemote, nil)
 	if err != nil {
 		return err
 	}
@@ -230,7 +193,7 @@ func (l *Libvirt) listen() {
 		}
 
 		// payload: packet length minus what was previously read
-		size := int(length) - (packetLengthSize + headerSize)
+		size := int(length) - (constants.PacketLengthSize + constants.HeaderSize)
 		buf := make([]byte, size)
 		for n := 0; n < size; {
 			nn, err := l.r.Read(buf)
@@ -260,7 +223,7 @@ func (l *Libvirt) callback(id uint32, res response) {
 // route sends incoming packets to their listeners.
 func (l *Libvirt) route(h *header, buf []byte) {
 	// route events to their respective listener
-	if h.Program == programQEMU && h.Procedure == qemuDomainMonitorEvent {
+	if h.Program == constants.ProgramQEMU && h.Procedure == constants.QEMUDomainMonitorEvent {
 		l.stream(buf)
 		return
 	}
@@ -320,7 +283,7 @@ func (l *Libvirt) removeStream(id uint32) error {
 		return err
 	}
 
-	resp, err := l.request(qemuConnectDomainMonitorEventDeregister, programQEMU, &buf)
+	resp, err := l.request(constants.QEMUConnectDomainMonitorEventDeregister, constants.ProgramQEMU, &buf)
 	if err != nil {
 		return err
 	}
@@ -361,7 +324,7 @@ func (l *Libvirt) request(proc uint32, program uint32, payload *bytes.Buffer) (<
 
 	l.register(serial, c)
 
-	size := packetLengthSize + headerSize
+	size := constants.PacketLengthSize + constants.HeaderSize
 	if payload != nil {
 		size += payload.Len()
 	}
@@ -370,7 +333,7 @@ func (l *Libvirt) request(proc uint32, program uint32, payload *bytes.Buffer) (<
 		Len: uint32(size),
 		Header: header{
 			Program:   program,
-			Version:   programVersion,
+			Version:   constants.ProgramVersion,
 			Procedure: proc,
 			Type:      Call,
 			Serial:    serial,
@@ -442,7 +405,7 @@ func decodeEvent(buf []byte) (*DomainEvent, error) {
 // If an error is encountered reading the provided Reader, the
 // error is returned and response length will be 0.
 func pktlen(r io.Reader) (uint32, error) {
-	buf := make([]byte, packetLengthSize)
+	buf := make([]byte, constants.PacketLengthSize)
 
 	for n := 0; n < cap(buf); {
 		nn, err := r.Read(buf)
@@ -458,7 +421,7 @@ func pktlen(r io.Reader) (uint32, error) {
 
 // extractHeader returns the decoded header from an incoming response.
 func extractHeader(r io.Reader) (*header, error) {
-	buf := make([]byte, headerSize)
+	buf := make([]byte, constants.HeaderSize)
 
 	for n := 0; n < cap(buf); {
 		nn, err := r.Read(buf)
diff --git a/rpc_test.go b/rpc_test.go
index 391a7bf..ae84340 100644
--- a/rpc_test.go
+++ b/rpc_test.go
@@ -20,11 +20,13 @@ import (
 	"testing"
 
 	"github.com/davecgh/go-xdr/xdr2"
+	"github.com/digitalocean/go-libvirt/internal/constants"
+	"github.com/digitalocean/go-libvirt/libvirttest"
 )
 
 var (
 	// dc229f87d4de47198cfd2e21c6105b01
-	testUUID = [uuidSize]byte{
+	testUUID = [constants.UUIDSize]byte{
 		0xdc, 0x22, 0x9f, 0x87, 0xd4, 0xde, 0x47, 0x19,
 		0x8c, 0xfd, 0x2e, 0x21, 0xc6, 0x10, 0x5b, 0x01,
 	}
@@ -118,16 +120,16 @@ func TestExtractHeader(t *testing.T) {
 		t.Error(err)
 	}
 
-	if h.Program != programRemote {
-		t.Errorf("expected Program %q, got %q", programRemote, h.Program)
+	if h.Program != constants.ProgramRemote {
+		t.Errorf("expected Program %q, got %q", constants.ProgramRemote, h.Program)
 	}
 
-	if h.Version != programVersion {
-		t.Errorf("expected version %q, got %q", programVersion, h.Version)
+	if h.Version != constants.ProgramVersion {
+		t.Errorf("expected version %q, got %q", constants.ProgramVersion, h.Version)
 	}
 
-	if h.Procedure != procConnectOpen {
-		t.Errorf("expected procedure %q, got %q", procConnectOpen, h.Procedure)
+	if h.Procedure != constants.ProcConnectOpen {
+		t.Errorf("expected procedure %q, got %q", constants.ProcConnectOpen, h.Procedure)
 	}
 
 	if h.Type != Call {
@@ -270,7 +272,7 @@ func TestAddStream(t *testing.T) {
 func TestRemoveStream(t *testing.T) {
 	id := uint32(1)
 
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 	l.events[id] = make(chan *DomainEvent)
 
@@ -328,7 +330,7 @@ func TestLookup(t *testing.T) {
 	c := make(chan response)
 	name := "test"
 
-	conn := setupTest()
+	conn := libvirttest.New()
 	l := New(conn)
 
 	l.register(id, c)