diff --git a/dsc.go b/dsc.go
index 5f919f5..0edf769 100644
--- a/dsc.go
+++ b/dsc.go
@@ -92,7 +92,7 @@ type DSC struct {
 	// MMSI of ship in distress (10 digits or empty)
 	// > The call content is next described as having a "self-identification" element. This is simply the sending
 	// > station's MMSI, encoded like the address element. This identifies who sent the message.
-	MSSI string
+	MMSI string
 
 	// DistressCause is The cause of the distress (2 digits or empty)
 	DistressCause string
@@ -117,7 +117,7 @@ func newDSC(s BaseSentence) (DSC, error) {
 		CommandTypeOrTeleCommand2:   p.String(4, "type of communication or second telecommand"),
 		PositionOrCanal:             p.String(5, "position or canal"),
 		TimeOrTelephoneNumber:       p.String(6, "time or telephone"),
-		MSSI:                        p.String(7, "MSSI"),
+		MMSI:                        p.String(7, "MMSI"),
 		DistressCause:               p.String(8, "distress cause"),
 		Acknowledgement: strings.TrimSpace(p.EnumString(
 			9,
diff --git a/dsc_test.go b/dsc_test.go
index 52bd16b..d1514b1 100644
--- a/dsc_test.go
+++ b/dsc_test.go
@@ -23,7 +23,7 @@ func TestDSC(t *testing.T) {
 				CommandTypeOrTeleCommand2:   "00",
 				PositionOrCanal:             "1423108312",
 				TimeOrTelephoneNumber:       "2019",
-				MSSI:                        " ",
+				MMSI:                        " ",
 				DistressCause:               "  ",
 				Acknowledgement:             "S",
 				ExpansionIndicator:          " E  ",
@@ -40,7 +40,7 @@ func TestDSC(t *testing.T) {
 				CommandTypeOrTeleCommand2:   "00",
 				PositionOrCanal:             "1423108312",
 				TimeOrTelephoneNumber:       "0236",
-				MSSI:                        "3381581370",
+				MMSI:                        "3381581370",
 				DistressCause:               " ",
 				Acknowledgement:             "S",
 				ExpansionIndicator:          "    ",
@@ -57,7 +57,7 @@ func TestDSC(t *testing.T) {
 				CommandTypeOrTeleCommand2:   "26",
 				PositionOrCanal:             "1423108312",
 				TimeOrTelephoneNumber:       "1902",
-				MSSI:                        " ",
+				MMSI:                        " ",
 				DistressCause:               " ",
 				Acknowledgement:             "B",
 				ExpansionIndicator:          " E  ",
diff --git a/dse.go b/dse.go
index 14b447e..a4d0d02 100644
--- a/dse.go
+++ b/dse.go
@@ -25,7 +25,7 @@ type DSE struct {
 	TotalNumber     int64  // total number of sentences, 01 to 99
 	Number          int64  // number of current sentence, 01 to 99
 	Acknowledgement string // Acknowledgement (R=Acknowledge request, B=Acknowledgement, S=Neither (end of sequence))
-	MSSI            string // MMSI of vessel (10 digits)
+	MMSI            string // MMSI of vessel (10 digits)
 	DataSets        []DSEDataSet
 }
 
@@ -56,7 +56,7 @@ func newDSE(s BaseSentence) (DSE, error) {
 		TotalNumber:     p.Int64(0, "total number of sentences"),
 		Number:          p.Int64(1, "sentence number"),
 		Acknowledgement: p.EnumString(2, "acknowledgement", AcknowledgementAutomaticDSE, AcknowledgementRequestDSE, AcknowledgementQueryDSE),
-		MSSI:            p.String(3, "MSSI"),
+		MMSI:            p.String(3, "MMSI"),
 		DataSets:        nil,
 	}
 	datasetFieldCount := len(p.Fields) - 4
diff --git a/dse_test.go b/dse_test.go
index 1d7be57..fcc2952 100644
--- a/dse_test.go
+++ b/dse_test.go
@@ -19,7 +19,7 @@ func TestDSE(t *testing.T) {
 				TotalNumber:     1,
 				Number:          1,
 				Acknowledgement: AcknowledgementAutomaticDSE,
-				MSSI:            "3380400790",
+				MMSI:            "3380400790",
 				DataSets: []DSEDataSet{
 					{Code: "00", Data: "46504437"},
 				},
@@ -32,7 +32,7 @@ func TestDSE(t *testing.T) {
 				TotalNumber:     1,
 				Number:          1,
 				Acknowledgement: AcknowledgementAutomaticDSE,
-				MSSI:            "3380400790",
+				MMSI:            "3380400790",
 				DataSets: []DSEDataSet{
 					{Code: "00", Data: "46504437"},
 					{Code: "01", Data: "16501437"},