diff --git a/soap/types.go b/soap/types.go
index 74556a8..fc2ba3e 100644
--- a/soap/types.go
+++ b/soap/types.go
@@ -19,6 +19,68 @@ var (
 	localLoc = time.Local
 )
 
+func MarshalUi1(v uint8) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi1(s string) (uint8, error) {
+	v, err := strconv.ParseUint(s, 10, 8)
+	return uint8(v), err
+}
+
+func MarshalUi2(v uint16) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi2(s string) (uint16, error) {
+	v, err := strconv.ParseUint(s, 10, 16)
+	return uint16(v), err
+}
+
+func MarshalUi4(v uint32) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi4(s string) (uint32, error) {
+	v, err := strconv.ParseUint(s, 10, 32)
+	return uint32(v), err
+}
+
+func MarshalI1(v int8) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI1(s string) (int8, error) {
+	v, err := strconv.ParseInt(s, 10, 8)
+	return int8(v), err
+}
+
+func MarshalI2(v int16) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI2(s string) (int16, error) {
+	v, err := strconv.ParseInt(s, 10, 16)
+	return int16(v), err
+}
+
+func MarshalI4(v int32) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI4(s string) (int32, error) {
+	v, err := strconv.ParseInt(s, 10, 32)
+	return int32(v), err
+}
+
+func MarshalInt(v int64) (string, error) {
+	return strconv.FormatInt(v, 10), nil
+}
+
+func UnmarshalInt(s string) (int64, error) {
+	return strconv.ParseInt(s, 10, 64)
+}
+
 // MarshalFixed14_4 marshals float64 to SOAP "fixed.14.4" type.
 func MarshalFixed14_4(v float64) (string, error) {
 	if v >= 1e14 || v <= -1e14 {
diff --git a/soap/types_test.go b/soap/types_test.go
index cdf35ef..da68161 100644
--- a/soap/types_test.go
+++ b/soap/types_test.go
@@ -16,7 +16,7 @@ type convTest interface {
 // duper is an interface that convTest values may optionally also implement to
 // generate another convTest for a value in an otherwise identical testCase.
 type duper interface {
-	Dupe(tag string) convTest
+	Dupe(tag string) []convTest
 }
 
 type testCase struct {
@@ -29,6 +29,108 @@ type testCase struct {
 	tag              string
 }
 
+type Ui1Test uint8
+
+func (v Ui1Test) Marshal() (string, error) {
+	return MarshalUi1(uint8(v))
+}
+func (v Ui1Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi1(s)
+}
+func (v Ui1Test) Equal(result interface{}) bool {
+	return uint8(v) == result.(uint8)
+}
+func (v Ui1Test) Dupe(tag string) []convTest {
+	if tag == "dupe" {
+		return []convTest{
+			Ui2Test(v),
+			Ui4Test(v),
+		}
+	}
+	return nil
+}
+
+type Ui2Test uint16
+
+func (v Ui2Test) Marshal() (string, error) {
+	return MarshalUi2(uint16(v))
+}
+func (v Ui2Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi2(s)
+}
+func (v Ui2Test) Equal(result interface{}) bool {
+	return uint16(v) == result.(uint16)
+}
+
+type Ui4Test uint32
+
+func (v Ui4Test) Marshal() (string, error) {
+	return MarshalUi4(uint32(v))
+}
+func (v Ui4Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi4(s)
+}
+func (v Ui4Test) Equal(result interface{}) bool {
+	return uint32(v) == result.(uint32)
+}
+
+type I1Test int8
+
+func (v I1Test) Marshal() (string, error) {
+	return MarshalI1(int8(v))
+}
+func (v I1Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI1(s)
+}
+func (v I1Test) Equal(result interface{}) bool {
+	return int8(v) == result.(int8)
+}
+func (v I1Test) Dupe(tag string) []convTest {
+	if tag == "dupe" {
+		return []convTest{
+			I2Test(v),
+			I4Test(v),
+		}
+	}
+	return nil
+}
+
+type I2Test int16
+
+func (v I2Test) Marshal() (string, error) {
+	return MarshalI2(int16(v))
+}
+func (v I2Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI2(s)
+}
+func (v I2Test) Equal(result interface{}) bool {
+	return int16(v) == result.(int16)
+}
+
+type I4Test int32
+
+func (v I4Test) Marshal() (string, error) {
+	return MarshalI4(int32(v))
+}
+func (v I4Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI4(s)
+}
+func (v I4Test) Equal(result interface{}) bool {
+	return int32(v) == result.(int32)
+}
+
+type IntTest int64
+
+func (v IntTest) Marshal() (string, error) {
+	return MarshalInt(int64(v))
+}
+func (v IntTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalInt(s)
+}
+func (v IntTest) Equal(result interface{}) bool {
+	return int64(v) == result.(int64)
+}
+
 type Fixed14_4Test float64
 
 func (v Fixed14_4Test) Marshal() (string, error) {
@@ -64,9 +166,9 @@ func (v DateTest) Unmarshal(s string) (interface{}, error) {
 func (v DateTest) Equal(result interface{}) bool {
 	return v.Time.Equal(result.(time.Time))
 }
-func (v DateTest) Dupe(tag string) convTest {
+func (v DateTest) Dupe(tag string) []convTest {
 	if tag != "no:dateTime" {
-		return DateTimeTest{v.Time}
+		return []convTest{DateTimeTest{v.Time}}
 	}
 	return nil
 }
@@ -84,9 +186,9 @@ func (v TimeOfDayTest) Unmarshal(s string) (interface{}, error) {
 func (v TimeOfDayTest) Equal(result interface{}) bool {
 	return v.TimeOfDay == result.(TimeOfDay)
 }
-func (v TimeOfDayTest) Dupe(tag string) convTest {
+func (v TimeOfDayTest) Dupe(tag string) []convTest {
 	if tag != "no:time.tz" {
-		return TimeOfDayTzTest{v.TimeOfDay}
+		return []convTest{TimeOfDayTzTest{v.TimeOfDay}}
 	}
 	return nil
 }
@@ -116,9 +218,9 @@ func (v DateTimeTest) Unmarshal(s string) (interface{}, error) {
 func (v DateTimeTest) Equal(result interface{}) bool {
 	return v.Time.Equal(result.(time.Time))
 }
-func (v DateTimeTest) Dupe(tag string) convTest {
+func (v DateTimeTest) Dupe(tag string) []convTest {
 	if tag != "no:dateTime.tz" {
-		return DateTimeTzTest{v.Time}
+		return []convTest{DateTimeTzTest{v.Time}}
 	}
 	return nil
 }
@@ -184,6 +286,53 @@ func Test(t *testing.T) {
 	}()
 
 	tests := []testCase{
+		// ui1
+		{str: "", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: " ", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "abc", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "-1", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "0", value: Ui1Test(0), tag: "dupe"},
+		{str: "1", value: Ui1Test(1), tag: "dupe"},
+		{str: "255", value: Ui1Test(255), tag: "dupe"},
+		{str: "256", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// ui2
+		{str: "65535", value: Ui2Test(65535)},
+		{str: "65536", value: Ui2Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// ui4
+		{str: "4294967295", value: Ui4Test(4294967295)},
+		{str: "4294967296", value: Ui4Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i1
+		{str: "", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: " ", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "abc", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "0", value: I1Test(0), tag: "dupe"},
+		{str: "-1", value: I1Test(-1), tag: "dupe"},
+		{str: "127", value: I1Test(127), tag: "dupe"},
+		{str: "-128", value: I1Test(-128), tag: "dupe"},
+		{str: "128", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-129", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i2
+		{str: "32767", value: I2Test(32767)},
+		{str: "-32768", value: I2Test(-32768)},
+		{str: "32768", value: I2Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-32769", value: I2Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i4
+		{str: "2147483647", value: I4Test(2147483647)},
+		{str: "-2147483648", value: I4Test(-2147483648)},
+		{str: "2147483648", value: I4Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-2147483649", value: I4Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// int
+		{str: "9223372036854775807", value: IntTest(9223372036854775807)},
+		{str: "-9223372036854775808", value: IntTest(-9223372036854775808)},
+		{str: "9223372036854775808", value: IntTest(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-9223372036854775809", value: IntTest(0), wantUnmarshalErr: true, noMarshal: true},
+
 		// fixed.14.4
 		{str: "0.0000", value: Fixed14_4Test(0)},
 		{str: "1.0000", value: Fixed14_4Test(1)},
@@ -300,8 +449,8 @@ func Test(t *testing.T) {
 	var extras []testCase
 	for i := range tests {
 		if duper, ok := tests[i].value.(duper); ok {
-			duped := duper.Dupe(tests[i].tag)
-			if duped != nil {
+			dupes := duper.Dupe(tests[i].tag)
+			for _, duped := range dupes {
 				dupedCase := testCase(tests[i])
 				dupedCase.value = duped
 				extras = append(extras, dupedCase)