diff --git a/smpp/transmitter.go b/smpp/transmitter.go
index 071dbb4..6178d1f 100644
--- a/smpp/transmitter.go
+++ b/smpp/transmitter.go
@@ -327,7 +327,7 @@ func (t *Transmitter) Submit(sm *ShortMessage) (*ShortMessage, error) {
 // SubmitLongMsg sends a long message (more than 140 bytes)
 // and returns and updates the given sm with the response status.
 // It returns the same sm object.
-func (t *Transmitter) SubmitLongMsg(sm *ShortMessage) (*ShortMessage, error) {
+func (t *Transmitter) SubmitLongMsg(sm *ShortMessage) ([]ShortMessage, error) {
 	maxLen := 133 // 140-7 (UDH with 2 byte reference number)
 	if sm.Text.Type() == pdutext.UCS2Type {
 		maxLen = 132 // to avoid a character being split between payloads
@@ -335,6 +335,8 @@ func (t *Transmitter) SubmitLongMsg(sm *ShortMessage) (*ShortMessage, error) {
 	rawMsg := sm.Text.Encode()
 	countParts := int((len(rawMsg)-1)/maxLen) + 1
 
+	parts := make([]ShortMessage, 0, countParts)
+
 	t.rMutex.Lock()
 	rn := uint16(t.r.Intn(0xFFFF))
 	t.rMutex.Unlock()
@@ -380,19 +382,20 @@ func (t *Transmitter) SubmitLongMsg(sm *ShortMessage) (*ShortMessage, error) {
 		sm.resp.p = resp.PDU
 		sm.resp.Unlock()
 		if resp.PDU == nil {
-			return nil, fmt.Errorf("unexpected empty PDU")
+			return parts, fmt.Errorf("unexpected empty PDU")
 		}
 		if id := resp.PDU.Header().ID; id != pdu.SubmitSMRespID {
-			return sm, fmt.Errorf("unexpected PDU ID: %s", id)
+			return parts, fmt.Errorf("unexpected PDU ID: %s", id)
 		}
 		if s := resp.PDU.Header().Status; s != 0 {
-			return sm, s
+			return parts, s
 		}
 		if resp.Err != nil {
-			return sm, resp.Err
+			return parts, resp.Err
 		}
+		parts = append(parts, *sm)
 	}
-	return sm, nil
+	return parts, nil
 }
 
 func (t *Transmitter) submitMsg(sm *ShortMessage, p pdu.Body, dataCoding uint8) (*ShortMessage, error) {
diff --git a/smpp/transmitter_test.go b/smpp/transmitter_test.go
index 8233b10..c5f0f91 100644
--- a/smpp/transmitter_test.go
+++ b/smpp/transmitter_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/fiorix/go-smpp/smpp/pdu/pdufield"
 	"github.com/fiorix/go-smpp/smpp/pdu/pdutext"
 	"github.com/fiorix/go-smpp/smpp/smpptest"
+	"fmt"
 )
 
 func TestShortMessage(t *testing.T) {
@@ -121,12 +122,14 @@ func TestShortMessageWindowSize(t *testing.T) {
 
 func TestLongMessage(t *testing.T) {
 	s := smpptest.NewUnstartedServer()
+	count := 0
 	s.Handler = func(c smpptest.Conn, p pdu.Body) {
 		switch p.Header().ID {
 		case pdu.SubmitSMID:
 			r := pdu.NewSubmitSMResp()
 			r.Header().Seq = p.Header().Seq
-			r.Fields().Set(pdufield.MessageID, "foobar")
+			r.Fields().Set(pdufield.MessageID, fmt.Sprintf("foobar%d", count))
+			count++
 			c.Write(r)
 		default:
 			smpptest.EchoHandler(c, p)
@@ -146,7 +149,7 @@ func TestLongMessage(t *testing.T) {
 	default:
 		t.Fatal(conn.Error())
 	}
-	sm, err := tx.SubmitLongMsg(&ShortMessage{
+	parts, err := tx.SubmitLongMsg(&ShortMessage{
 		Src:      "root",
 		Dst:      "foobar",
 		Text:     pdutext.Raw("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam consequat nisl enim, vel finibus neque aliquet sit amet. Interdum et malesuada fames ac ante ipsum primis in faucibus."),
@@ -156,12 +159,17 @@ func TestLongMessage(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	msgid := sm.RespID()
-	if msgid == "" {
-		t.Fatalf("pdu does not contain msgid: %#v", sm.Resp())
+	if len(parts) != 2 {
+		t.Fatalf("expected %d responses, but received %d", 2, len(parts))
 	}
-	if msgid != "foobar" {
-		t.Fatalf("unexpected msgid: want foobar, have %q", msgid)
+	for index, sm := range parts {
+		msgid := sm.RespID()
+		if msgid == "" {
+			t.Fatalf("pdu does not contain msgid: %#v", sm.Resp())
+		}
+		if msgid != fmt.Sprintf("foobar%d", index) {
+			t.Fatalf("unexpected msgid: want foobar%d, have %q", index, msgid)
+		}
 	}
 }
 
@@ -169,12 +177,14 @@ func TestLongMessageAsUCS2(t *testing.T) {
 	s := smpptest.NewUnstartedServer()
 	var receivedMsg string
 	shortMsg := "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam consequat nisl enim, vel finibus neque aliquet sit amet. Interdum et malesuada fames ac ante ipsum primis in faucibus. ✓"
+	count := 0
 	s.Handler = func(c smpptest.Conn, p pdu.Body) {
 		switch p.Header().ID {
 		case pdu.SubmitSMID:
 			r := pdu.NewSubmitSMResp()
 			r.Header().Seq = p.Header().Seq
-			r.Fields().Set(pdufield.MessageID, "foobar")
+			r.Fields().Set(pdufield.MessageID, fmt.Sprintf("foobar%d", count))
+			count++
 			smByts := p.Fields()[pdufield.ShortMessage].Bytes()
 			switch pdutext.DataCoding(p.Fields()[pdufield.DataCoding].Raw().(uint8)) {
 			case pdutext.Latin1Type:
@@ -203,7 +213,7 @@ func TestLongMessageAsUCS2(t *testing.T) {
 	default:
 		t.Fatal(conn.Error())
 	}
-	sm, err := tx.SubmitLongMsg(&ShortMessage{
+	parts, err := tx.SubmitLongMsg(&ShortMessage{
 		Src:      "root",
 		Dst:      "foobar",
 		Text:     pdutext.UCS2(shortMsg),
@@ -213,17 +223,22 @@ func TestLongMessageAsUCS2(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	msgid := sm.RespID()
-	if msgid == "" {
-		t.Fatalf("pdu does not contain msgid: %#v", sm.Resp())
+	if len(parts) != 3 {
+		t.Fatalf("expected %d responses, but received %d", 3, len(parts))
 	}
+	for index, sm := range parts {
+		msgid := sm.RespID()
+		if msgid == "" {
+			t.Fatalf("pdu does not contain msgid: %#v", sm.Resp())
+		}
 
-	if receivedMsg != shortMsg {
-		t.Fatalf("receivedMsg: %v, does not match shortMsg: %v", receivedMsg, shortMsg)
-	}
+		if receivedMsg != shortMsg {
+			t.Fatalf("receivedMsg: %v, does not match shortMsg: %v", receivedMsg, shortMsg)
+		}
 
-	if msgid != "foobar" {
-		t.Fatalf("unexpected msgid: want foobar, have %q", msgid)
+		if msgid != fmt.Sprintf("foobar%d", index) {
+			t.Fatalf("unexpected msgid: want foobar%d, have %q", index, msgid)
+		}
 	}
 }