diff --git a/src/pkg/encoding/xml/marshal.go b/src/pkg/encoding/xml/marshal.go
index 7a05a1bb10e..a2e47cf9b83 100644
--- a/src/pkg/encoding/xml/marshal.go
+++ b/src/pkg/encoding/xml/marshal.go
@@ -52,6 +52,10 @@ const (
 //     - a field with tag ",comment" is written as an XML comment, not
 //       subject to the usual marshalling procedure. It must not contain
 //       the "--" string within it.
+//     - a field with a tag including the "omitempty" option is omitted
+//       if the field value is empty. The empty values are false, 0, any
+//       nil pointer or interface value, and any array, slice, map, or
+//       string of length zero.
 //
 // If a field uses a tag "a>b>c", then the element c will be nested inside
 // parent elements a and b.  Fields that appear next to each other that name
@@ -63,6 +67,8 @@ const (
 //		FirstName string   `xml:"person>name>first"`
 //		LastName  string   `xml:"person>name>last"`
 //		Age       int      `xml:"person>age"`
+//		Height    float    `xml:"person>height,omitempty"`
+//		Married   bool     `xml:"person>married"`
 //	}
 //
 //	xml.Marshal(&Result{Id: 13, FirstName: "John", LastName: "Doe", Age: 42})
@@ -76,6 +82,7 @@ const (
 //				<last>Doe</last>
 //			</name>
 //			<age>42</age>
+//			<married>false</married>
 //		</person>
 //	</result>
 //
@@ -116,6 +123,9 @@ func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo) error {
 	if !val.IsValid() {
 		return nil
 	}
+	if finfo != nil && finfo.flags&fOmitEmpty != 0 && isEmptyValue(val) {
+		return nil
+	}
 
 	kind := val.Kind()
 	typ := val.Type()
@@ -183,12 +193,8 @@ func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo) error {
 			continue
 		}
 		fv := val.FieldByIndex(finfo.idx)
-		switch fv.Kind() {
-		case reflect.String, reflect.Array, reflect.Slice:
-			// TODO: Should we really do this once ,omitempty is in?
-			if fv.Len() == 0 {
-				continue
-			}
+		if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) {
+			continue
 		}
 		p.WriteByte(' ')
 		p.WriteString(finfo.name)
@@ -378,3 +384,21 @@ type UnsupportedTypeError struct {
 func (e *UnsupportedTypeError) Error() string {
 	return "xml: unsupported type: " + e.Type.String()
 }
+
+func isEmptyValue(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		return v.Len() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	}
+	return false
+}
diff --git a/src/pkg/encoding/xml/marshal_test.go b/src/pkg/encoding/xml/marshal_test.go
index 0f6c0f0795d..ce51ea82b97 100644
--- a/src/pkg/encoding/xml/marshal_test.go
+++ b/src/pkg/encoding/xml/marshal_test.go
@@ -38,14 +38,14 @@ type NamedType string
 
 type Port struct {
 	XMLName struct{} `xml:"port"`
-	Type    string   `xml:"type,attr"`
+	Type    string   `xml:"type,attr,omitempty"`
 	Comment string   `xml:",comment"`
 	Number  string   `xml:",chardata"`
 }
 
 type Domain struct {
 	XMLName struct{} `xml:"domain"`
-	Country string   `xml:",attr"`
+	Country string   `xml:",attr,omitempty"`
 	Name    []byte   `xml:",chardata"`
 	Comment []byte   `xml:",comment"`
 }
@@ -149,11 +149,33 @@ type NameInField struct {
 
 type AttrTest struct {
 	Int   int     `xml:",attr"`
-	Lower int     `xml:"int,attr"`
+	Named int     `xml:"int,attr"`
 	Float float64 `xml:",attr"`
 	Uint8 uint8   `xml:",attr"`
 	Bool  bool    `xml:",attr"`
 	Str   string  `xml:",attr"`
+	Bytes []byte  `xml:",attr"`
+}
+
+type OmitAttrTest struct {
+	Int   int     `xml:",attr,omitempty"`
+	Named int     `xml:"int,attr,omitempty"`
+	Float float64 `xml:",attr,omitempty"`
+	Uint8 uint8   `xml:",attr,omitempty"`
+	Bool  bool    `xml:",attr,omitempty"`
+	Str   string  `xml:",attr,omitempty"`
+	Bytes []byte  `xml:",attr,omitempty"`
+}
+
+type OmitFieldTest struct {
+	Int   int           `xml:",omitempty"`
+	Named int           `xml:"int,omitempty"`
+	Float float64       `xml:",omitempty"`
+	Uint8 uint8         `xml:",omitempty"`
+	Bool  bool          `xml:",omitempty"`
+	Str   string        `xml:",omitempty"`
+	Bytes []byte        `xml:",omitempty"`
+	Ptr   *PresenceTest `xml:",omitempty"`
 }
 
 type AnyTest struct {
@@ -549,13 +571,65 @@ var marshalTests = []struct {
 	{
 		Value: &AttrTest{
 			Int:   8,
-			Lower: 9,
+			Named: 9,
 			Float: 23.5,
 			Uint8: 255,
 			Bool:  true,
-			Str:   "s",
+			Str:   "str",
+			Bytes: []byte("byt"),
 		},
-		ExpectXML: `<AttrTest Int="8" int="9" Float="23.5" Uint8="255" Bool="true" Str="s"></AttrTest>`,
+		ExpectXML: `<AttrTest Int="8" int="9" Float="23.5" Uint8="255"` +
+			` Bool="true" Str="str" Bytes="byt"></AttrTest>`,
+	},
+	{
+		Value: &AttrTest{Bytes: []byte{}},
+		ExpectXML: `<AttrTest Int="0" int="0" Float="0" Uint8="0"` +
+			` Bool="false" Str="" Bytes=""></AttrTest>`,
+	},
+	{
+		Value: &OmitAttrTest{
+			Int:   8,
+			Named: 9,
+			Float: 23.5,
+			Uint8: 255,
+			Bool:  true,
+			Str:   "str",
+			Bytes: []byte("byt"),
+		},
+		ExpectXML: `<OmitAttrTest Int="8" int="9" Float="23.5" Uint8="255"` +
+			` Bool="true" Str="str" Bytes="byt"></OmitAttrTest>`,
+	},
+	{
+		Value:     &OmitAttrTest{},
+		ExpectXML: `<OmitAttrTest></OmitAttrTest>`,
+	},
+
+	// omitempty on fields
+	{
+		Value: &OmitFieldTest{
+			Int:   8,
+			Named: 9,
+			Float: 23.5,
+			Uint8: 255,
+			Bool:  true,
+			Str:   "str",
+			Bytes: []byte("byt"),
+			Ptr:   &PresenceTest{},
+		},
+		ExpectXML: `<OmitFieldTest>` +
+			`<Int>8</Int>` +
+			`<int>9</int>` +
+			`<Float>23.5</Float>` +
+			`<Uint8>255</Uint8>` +
+			`<Bool>true</Bool>` +
+			`<Str>str</Str>` +
+			`<Bytes>byt</Bytes>` +
+			`<Ptr></Ptr>` +
+			`</OmitFieldTest>`,
+	},
+	{
+		Value:     &OmitFieldTest{},
+		ExpectXML: `<OmitFieldTest></OmitFieldTest>`,
 	},
 
 	// Test ",any"
diff --git a/src/pkg/encoding/xml/read_test.go b/src/pkg/encoding/xml/read_test.go
index 833eafc9a58..a3b0b1d594f 100644
--- a/src/pkg/encoding/xml/read_test.go
+++ b/src/pkg/encoding/xml/read_test.go
@@ -97,7 +97,7 @@ type Entry struct {
 }
 
 type Link struct {
-	Rel  string `xml:"rel,attr"`
+	Rel  string `xml:"rel,attr,omitempty"`
 	Href string `xml:"href,attr"`
 }
 
@@ -109,7 +109,7 @@ type Person struct {
 }
 
 type Text struct {
-	Type string `xml:"type,attr"`
+	Type string `xml:"type,attr,omitempty"`
 	Body string `xml:",chardata"`
 }
 
diff --git a/src/pkg/encoding/xml/typeinfo.go b/src/pkg/encoding/xml/typeinfo.go
index 5475f290d18..8e2e4508b10 100644
--- a/src/pkg/encoding/xml/typeinfo.go
+++ b/src/pkg/encoding/xml/typeinfo.go
@@ -36,8 +36,7 @@ const (
 	fComment
 	fAny
 
-	// TODO:
-	//fOmitEmpty
+	fOmitEmpty
 
 	fMode = fElement | fAttr | fCharData | fInnerXml | fComment | fAny
 )
@@ -133,20 +132,28 @@ func structFieldInfo(typ reflect.Type, f *reflect.StructField) (*fieldInfo, erro
 				finfo.flags |= fComment
 			case "any":
 				finfo.flags |= fAny
+			case "omitempty":
+				finfo.flags |= fOmitEmpty
 			}
 		}
 
 		// Validate the flags used.
+		valid := true
 		switch mode := finfo.flags & fMode; mode {
 		case 0:
 			finfo.flags |= fElement
 		case fAttr, fCharData, fInnerXml, fComment, fAny:
-			if f.Name != "XMLName" && (tag == "" || mode == fAttr) {
-				break
+			if f.Name == "XMLName" || tag != "" && mode != fAttr {
+				valid = false
 			}
-			fallthrough
 		default:
 			// This will also catch multiple modes in a single field.
+			valid = false
+		}
+		if finfo.flags&fOmitEmpty != 0 && finfo.flags&(fElement|fAttr) == 0 {
+			valid = false
+		}
+		if !valid {
 			return nil, fmt.Errorf("xml: invalid tag in field %s of type %s: %q",
 				f.Name, typ, f.Tag.Get("xml"))
 		}