diff --git a/errors.go b/errors.go
index f6a74fe..b0643eb 100644
--- a/errors.go
+++ b/errors.go
@@ -4,7 +4,7 @@ package iso8583
 // connection failed to unpack message
 type UnpackError struct {
 	Err        error
-	Field      string
+	FieldID    string
 	RawMessage []byte
 }
 
diff --git a/message.go b/message.go
index 32d5667..25b78a9 100644
--- a/message.go
+++ b/message.go
@@ -249,7 +249,7 @@ func (m *Message) unpack(src []byte) error {
 	if err != nil {
 		return &UnpackError{
 			Err:        fmt.Errorf("failed to unpack MTI: %w", err),
-			Field:      strconv.Itoa(mtiIdx),
+			FieldID:    strconv.Itoa(mtiIdx),
 			RawMessage: src,
 		}
 	}
@@ -263,7 +263,7 @@ func (m *Message) unpack(src []byte) error {
 	if err != nil {
 		return &UnpackError{
 			Err:        fmt.Errorf("failed to unpack bitmap: %w", err),
-			Field:      strconv.Itoa(bitmapIdx),
+			FieldID:    strconv.Itoa(bitmapIdx),
 			RawMessage: src,
 		}
 	}
@@ -281,7 +281,7 @@ func (m *Message) unpack(src []byte) error {
 			if !ok {
 				return &UnpackError{
 					Err:        fmt.Errorf("failed to unpack field %d: no specification found", i),
-					Field:      strconv.Itoa(i),
+					FieldID:    strconv.Itoa(i),
 					RawMessage: src,
 				}
 			}
@@ -290,7 +290,7 @@ func (m *Message) unpack(src []byte) error {
 			if err != nil {
 				return &UnpackError{
 					Err:        fmt.Errorf("failed to unpack field %d (%s): %w", i, fl.Spec().Description, err),
-					Field:      strconv.Itoa(i),
+					FieldID:    strconv.Itoa(i),
 					RawMessage: src,
 				}
 			}
diff --git a/message_test.go b/message_test.go
index 7ada7d3..9e7170b 100644
--- a/message_test.go
+++ b/message_test.go
@@ -762,7 +762,7 @@ func TestPackUnpack(t *testing.T) {
 		require.Error(t, err)
 		var unpackError *UnpackError
 		require.ErrorAs(t, err, &unpackError)
-		assert.Equal(t, unpackError.Field, "120")
+		assert.Equal(t, unpackError.FieldID, "120")
 
 		s, err := message.GetString(2)
 		require.NoError(t, err)