diff --git a/server_test.go b/server_test.go
index d726c50..858426b 100644
--- a/server_test.go
+++ b/server_test.go
@@ -22,7 +22,51 @@ func TestServer_StartStop(t *testing.T) {
 }
 
 func TestServer_Lookup(t *testing.T) {
-	serv, err := NewServer(&Config{Zone: makeServiceWithServiceName(t, "_foobar._tcp")})
+	entries := make(chan *ServiceEntry, 1)
+	errCh := make(chan error, 1)
+	defer close(errCh)
+	testCases := []struct {
+		description string
+		checkup     func()
+	}{
+		{description: "normal case", checkup: func() {
+			select {
+			case e := <-entries:
+				if e.Name != "hostname._foobar._tcp.local." {
+					errCh <- fmt.Errorf("Entry has the wrong name: %+v", e)
+					return
+				}
+				if e.Port != 80 {
+					errCh <- fmt.Errorf("Entry has the wrong port: %+v", e)
+					return
+				}
+				if e.Info != "Local web server" {
+					errCh <- fmt.Errorf("Entry as the wrong Info: %+v", e)
+					return
+				}
+				errCh <- nil
+			case <-time.After(80 * time.Millisecond):
+				errCh <- fmt.Errorf("Timed out waiting for response")
+			}
+		}}, {
+			description: "change txt",
+			checkup: func() {
+				select {
+				case e := <-entries:
+					if e.Info != "a=a|b=b" {
+						errCh <- fmt.Errorf("Entry as the wrong Info: %+v", e)
+						return
+					}
+					errCh <- nil
+				case <-time.After(80 * time.Millisecond):
+					errCh <- fmt.Errorf("Timed out waiting for response")
+				}
+			},
+		},
+	}
+
+	svc := makeServiceWithServiceName(t, "_foobar._tcp")
+	serv, err := NewServer(&Config{Zone: svc})
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -31,45 +75,26 @@ func TestServer_Lookup(t *testing.T) {
 			t.Fatalf("err: %v", err)
 		}
 	}()
-
-	entries := make(chan *ServiceEntry, 1)
-	errCh := make(chan error, 1)
-	defer close(errCh)
-	go func() {
-		select {
-		case e := <-entries:
-			if e.Name != "hostname._foobar._tcp.local." {
-				errCh <- fmt.Errorf("Entry has the wrong name: %+v", e)
-				return
-			}
-			if e.Port != 80 {
-				errCh <- fmt.Errorf("Entry has the wrong port: %+v", e)
-				return
-			}
-			if e.Info != "Local web server" {
-				errCh <- fmt.Errorf("Entry as the wrong Info: %+v", e)
-				return
-			}
-			errCh <- nil
-		case <-time.After(80 * time.Millisecond):
-			errCh <- fmt.Errorf("Timed out waiting for response")
+	for idx, testCase := range testCases {
+		go testCase.checkup()
+		if idx == 1 {
+			svc.UpdateTXT([]string{"a=a", "b=b"})
+		}
+		params := &QueryParam{
+			Service:     "_foobar._tcp",
+			Domain:      "local",
+			Timeout:     50 * time.Millisecond,
+			Entries:     entries,
+			DisableIPv6: true,
 		}
-	}()
-
-	params := &QueryParam{
-		Service:     "_foobar._tcp",
-		Domain:      "local",
-		Timeout:     50 * time.Millisecond,
-		Entries:     entries,
-		DisableIPv6: true,
-	}
-	err = Query(params)
-	if err != nil {
-		t.Fatalf("err: %v", err)
-	}
 
-	err = <-errCh
-	if err != nil {
-		t.Fatalf("err: %v", err)
+		err = Query(params)
+		if err != nil {
+			t.Fatalf("description: %s, err: %v", testCase.description, err)
+		}
+		err = <-errCh
+		if err != nil {
+			t.Fatalf("description: %s, err: %v", testCase.description, err)
+		}
 	}
 }
diff --git a/zone.go b/zone.go
index c9e8664..679f1f0 100644
--- a/zone.go
+++ b/zone.go
@@ -8,6 +8,7 @@ import (
 	"net"
 	"os"
 	"strings"
+	"sync"
 
 	"github.com/miekg/dns"
 )
@@ -26,6 +27,7 @@ type Zone interface {
 
 // MDNSService is used to export a named service by implementing a Zone
 type MDNSService struct {
+	mutex    sync.Mutex
 	Instance string   // Instance name (e.g. "hostService name")
 	Service  string   // Service name (e.g. "_http._tcp.")
 	Domain   string   // If blank, assumes "local"
@@ -302,9 +304,21 @@ func (m *MDNSService) instanceRecords(q dns.Question) []dns.RR {
 				Class:  dns.ClassINET,
 				Ttl:    defaultTTL,
 			},
-			Txt: m.TXT,
+			Txt: m.GetTXT(),
 		}
 		return []dns.RR{txt}
 	}
 	return nil
 }
+
+func (m *MDNSService) UpdateTXT(txt []string) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	m.TXT = txt
+}
+
+func (m *MDNSService) GetTXT() []string {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	return m.TXT
+}