diff --git a/negotiate_flags.go b/negotiate_flags.go
index 6c3ce7b..5905c02 100644
--- a/negotiate_flags.go
+++ b/negotiate_flags.go
@@ -7,30 +7,38 @@ const (
 	/*B*/ negotiateFlagNTLMNEGOTIATEOEM = 1 << 1
 	/*C*/ negotiateFlagNTLMSSPREQUESTTARGET = 1 << 2
 
-	/*D*/ negotiateFlagNTLMSSPNEGOTIATESIGN = 1 << 4
+	/*D*/
+	negotiateFlagNTLMSSPNEGOTIATESIGN = 1 << 4
 	/*E*/ negotiateFlagNTLMSSPNEGOTIATESEAL = 1 << 5
 	/*F*/ negotiateFlagNTLMSSPNEGOTIATEDATAGRAM = 1 << 6
 	/*G*/ negotiateFlagNTLMSSPNEGOTIATELMKEY = 1 << 7
 
-	/*H*/ negotiateFlagNTLMSSPNEGOTIATENTLM = 1 << 9
+	/*H*/
+	negotiateFlagNTLMSSPNEGOTIATENTLM = 1 << 9
 
-	/*J*/ negotiateFlagANONYMOUS = 1 << 11
+	/*J*/
+	negotiateFlagANONYMOUS = 1 << 11
 	/*K*/ negotiateFlagNTLMSSPNEGOTIATEOEMDOMAINSUPPLIED = 1 << 12
 	/*L*/ negotiateFlagNTLMSSPNEGOTIATEOEMWORKSTATIONSUPPLIED = 1 << 13
 
-	/*M*/ negotiateFlagNTLMSSPNEGOTIATEALWAYSSIGN = 1 << 15
+	/*M*/
+	negotiateFlagNTLMSSPNEGOTIATEALWAYSSIGN = 1 << 15
 	/*N*/ negotiateFlagNTLMSSPTARGETTYPEDOMAIN = 1 << 16
 	/*O*/ negotiateFlagNTLMSSPTARGETTYPESERVER = 1 << 17
 
-	/*P*/ negotiateFlagNTLMSSPNEGOTIATEEXTENDEDSESSIONSECURITY = 1 << 19
+	/*P*/
+	negotiateFlagNTLMSSPNEGOTIATEEXTENDEDSESSIONSECURITY = 1 << 19
 	/*Q*/ negotiateFlagNTLMSSPNEGOTIATEIDENTIFY = 1 << 20
 
-	/*R*/ negotiateFlagNTLMSSPREQUESTNONNTSESSIONKEY = 1 << 22
+	/*R*/
+	negotiateFlagNTLMSSPREQUESTNONNTSESSIONKEY = 1 << 22
 	/*S*/ negotiateFlagNTLMSSPNEGOTIATETARGETINFO = 1 << 23
 
-	/*T*/ negotiateFlagNTLMSSPNEGOTIATEVERSION = 1 << 25
+	/*T*/
+	negotiateFlagNTLMSSPNEGOTIATEVERSION = 1 << 25
 
-	/*U*/ negotiateFlagNTLMSSPNEGOTIATE128 = 1 << 29
+	/*U*/
+	negotiateFlagNTLMSSPNEGOTIATE128 = 1 << 29
 	/*V*/ negotiateFlagNTLMSSPNEGOTIATEKEYEXCH = 1 << 30
 	/*W*/ negotiateFlagNTLMSSPNEGOTIATE56 = 1 << 31
 )
diff --git a/negotiate_message.go b/negotiate_message.go
index 97aa07e..28f0537 100644
--- a/negotiate_message.go
+++ b/negotiate_message.go
@@ -3,29 +3,61 @@ package ntlmssp
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
+	"strings"
 )
 
+const expMsgBodyLen = 40
+
 type negotiateMessageFields struct {
 	messageHeader
 	NegotiateFlags negotiateFlags
+
+	Domain      varField
+	Workstation varField
+
+	Version
 }
 
+var defaultFlags = negotiateFlagNTLMSSPNEGOTIATETARGETINFO |
+	negotiateFlagNTLMSSPNEGOTIATE56 |
+	negotiateFlagNTLMSSPNEGOTIATE128 |
+	negotiateFlagNTLMSSPNEGOTIATEUNICODE
+
 //NewNegotiateMessage creates a new NEGOTIATE message with the
 //flags that this package supports.
-func NewNegotiateMessage() []byte {
-	m := negotiateMessageFields{
-		messageHeader: newMessageHeader(1),
+func NewNegotiateMessage(domainName, workstationName string) ([]byte, error) {
+	payloadOffset := expMsgBodyLen
+	flags := defaultFlags
+
+	if domainName != "" {
+		flags |= negotiateFlagNTLMSSPNEGOTIATEOEMDOMAINSUPPLIED
 	}
 
-	m.NegotiateFlags = negotiateFlagNTLMSSPREQUESTTARGET |
-		negotiateFlagNTLMSSPNEGOTIATENTLM |
-		negotiateFlagNTLMSSPNEGOTIATEALWAYSSIGN |
-		negotiateFlagNTLMSSPNEGOTIATEUNICODE
+	if workstationName != "" {
+		flags |= negotiateFlagNTLMSSPNEGOTIATEOEMWORKSTATIONSUPPLIED
+	}
+
+	msg := negotiateMessageFields{
+		messageHeader:  newMessageHeader(1),
+		NegotiateFlags: flags,
+		Domain:         newVarField(&payloadOffset, len(domainName)),
+		Workstation:    newVarField(&payloadOffset, len(workstationName)),
+		Version:        DefaultVersion(),
+	}
 
 	b := bytes.Buffer{}
-	err := binary.Write(&b, binary.LittleEndian, &m)
-	if err != nil {
-		panic(err)
+	if err := binary.Write(&b, binary.LittleEndian, &msg); err != nil {
+		return nil, err
 	}
-	return b.Bytes()
+	if b.Len() != expMsgBodyLen {
+		return nil, errors.New("incorrect body length")
+	}
+
+	payload := strings.ToUpper(domainName + workstationName)
+	if _, err := b.WriteString(payload); err != nil {
+		return nil, err
+	}
+
+	return b.Bytes(), nil
 }
diff --git a/negotiator.go b/negotiator.go
index 9ae4586..6e30454 100644
--- a/negotiator.go
+++ b/negotiator.go
@@ -6,8 +6,21 @@ import (
 	"io"
 	"io/ioutil"
 	"net/http"
+	"strings"
 )
 
+// GetDomain : parse domain name from based on slashes in the input
+func GetDomain(user string) (string, string) {
+	domain := ""
+
+	if strings.Contains(user, "\\") {
+		ucomponents := strings.SplitN(user, "\\", 2)
+		domain = ucomponents[0]
+		user = ucomponents[1]
+	}
+	return user, domain
+}
+
 //Negotiator is a http.Roundtripper decorator that automatically
 //converts basic authentication to NTLM/Negotiate authentication when appropriate.
 type Negotiator struct{ http.RoundTripper }
@@ -76,8 +89,15 @@ func (l Negotiator) RoundTrip(req *http.Request) (res *http.Response, err error)
 			return nil, err
 		}
 
+		// get domain from username
+		domain := ""
+		u, domain = GetDomain(u)
+
 		// send negotiate
-		negotiateMessage := NewNegotiateMessage()
+		negotiateMessage, err := NewNegotiateMessage(domain, "")
+		if err != nil {
+			return nil, err
+		}
 		if resauth.IsNTLM() {
 			req.Header.Set("Authorization", "NTLM "+base64.StdEncoding.EncodeToString(negotiateMessage))
 		} else {
diff --git a/nlmp_test.go b/nlmp_test.go
index dea5aaf..c0ece95 100644
--- a/nlmp_test.go
+++ b/nlmp_test.go
@@ -10,8 +10,62 @@ import (
 var username = "user"
 var password = "SecREt01"
 var target = "DOMAIN"
+var domain = "MYDOMAIN"
+var workstation = "MYPC"
 var challenge = []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef}
 
+func TestUsernameDomainWorkstation(t *testing.T) {
+	// taking a username and workstation as input, check that the username, domain, workstation
+	// and negotiate message bytes all match their expected values
+	tables := []struct {
+		u  string
+		w  string
+		xu string
+		xd string
+		xb []byte
+	}{
+		{username, "", username, "", []byte{
+			0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00,
+			0x80, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x28, 0x00, 0x00, 0x00, 0x06, 0x01, 0xb1, 0x1d, 0x00, 0x00, 0x00, 0x0f}},
+		{domain + "\\" + username, "", username, domain, []byte{
+			0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x10,
+			0x80, 0xa0, 0x08, 0x00, 0x08, 0x00, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x30, 0x00, 0x00, 0x00, 0x06, 0x01, 0xb1, 0x1d, 0x00, 0x00, 0x00, 0x0f, 0x4d, 0x59,
+			0x44, 0x4f, 0x4d, 0x41, 0x49, 0x4e}},
+		{domain + "\\" + username, workstation, username, domain, []byte{
+			0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x30,
+			0x80, 0xa0, 0x08, 0x00, 0x08, 0x00, 0x28, 0x00, 0x00, 0x00, 0x04, 0x00, 0x04, 0x00,
+			0x30, 0x00, 0x00, 0x00, 0x06, 0x01, 0xb1, 0x1d, 0x00, 0x00, 0x00, 0x0f, 0x4d, 0x59,
+			0x44, 0x4f, 0x4d, 0x41, 0x49, 0x4e, 0x4d, 0x59, 0x50, 0x43}},
+		{username, workstation, username, "", []byte{
+			0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x20,
+			0x80, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00, 0x04, 0x00, 0x04, 0x00,
+			0x28, 0x00, 0x00, 0x00, 0x06, 0x01, 0xb1, 0x1d, 0x00, 0x00, 0x00, 0x0f, 0x4d, 0x59,
+			0x50, 0x43}},
+	}
+
+	for _, table := range tables {
+		tuser, tdomain := GetDomain(table.u)
+		if tuser != table.xu {
+			t.Fatalf("username not correct, expected %v got %v", tuser, table.xu)
+		}
+		if tdomain != table.xd {
+			t.Fatalf("domain not correct, expected %v got %v", tdomain, table.xd)
+		}
+
+		tb, err := NewNegotiateMessage(tdomain, table.w)
+		if err != nil {
+			t.Fatalf("error creating new negotiate message with domain '%v' and workstation '%v'", tdomain, table.w)
+		}
+
+		if !bytes.Equal(tb, table.xb) {
+			t.Fatalf("negotiate message bytes not correct, expected %v got %v", tb, table.xb)
+		}
+	}
+
+}
+
 func TestCalculateNTLMv2Response(t *testing.T) {
 	NTLMv2Hash := getNtlmV2Hash(password, username, target)
 	ClientChallenge := []byte{0xff, 0xff, 0xff, 0x00, 0x11, 0x22, 0x33, 0x44}
diff --git a/version.go b/version.go
new file mode 100644
index 0000000..6d84892
--- /dev/null
+++ b/version.go
@@ -0,0 +1,20 @@
+package ntlmssp
+
+// Version is a struct representing https://msdn.microsoft.com/en-us/library/cc236654.aspx
+type Version struct {
+	ProductMajorVersion uint8
+	ProductMinorVersion uint8
+	ProductBuild        uint16
+	_                   [3]byte
+	NTLMRevisionCurrent uint8
+}
+
+// DefaultVersion returns a Version with "sensible" defaults (Windows 7)
+func DefaultVersion() Version {
+	return Version{
+		ProductMajorVersion: 6,
+		ProductMinorVersion: 1,
+		ProductBuild:        7601,
+		NTLMRevisionCurrent: 15,
+	}
+}