diff --git a/src/encoding/json/stream.go b/src/encoding/json/stream.go
index dba978aa66..87f0e57c6c 100644
--- a/src/encoding/json/stream.go
+++ b/src/encoding/json/stream.go
@@ -204,7 +204,10 @@ func (enc *Encoder) Encode(v interface{}) error {
 	e.WriteByte('\n')
 
 	b := e.Bytes()
-	if enc.indentBuf != nil {
+	if enc.indentPrefix != "" || enc.indentValue != "" {
+		if enc.indentBuf == nil {
+			enc.indentBuf = new(bytes.Buffer)
+		}
 		enc.indentBuf.Reset()
 		err = Indent(enc.indentBuf, b, enc.indentPrefix, enc.indentValue)
 		if err != nil {
@@ -219,9 +222,10 @@ func (enc *Encoder) Encode(v interface{}) error {
 	return err
 }
 
-// Indent sets the encoder to format each encoded value with Indent.
-func (enc *Encoder) Indent(prefix, indent string) {
-	enc.indentBuf = new(bytes.Buffer)
+// SetIndent instructs the encoder to format each subsequent encoded
+// value as if indented by the package-level function Indent(dst, src, prefix, indent).
+// Calling SetIndent("", "") disables indentation.
+func (enc *Encoder) SetIndent(prefix, indent string) {
 	enc.indentPrefix = prefix
 	enc.indentValue = indent
 }
@@ -230,7 +234,7 @@ func (enc *Encoder) Indent(prefix, indent string) {
 // should be escaped inside JSON quoted strings.
 // The default behavior is to escape &, <, and > to \u0026, \u003c, and \u003e
 // to avoid certain safety problems that can arise when embedding JSON in HTML.
-// 
+//
 // In non-HTML settings where the escaping interferes with the readability
 // of the output, SetEscapeHTML(false) disables this behavior.
 func (enc *Encoder) SetEscapeHTML(on bool) {
diff --git a/src/encoding/json/stream_test.go b/src/encoding/json/stream_test.go
index 0d578ce24d..84edeb187c 100644
--- a/src/encoding/json/stream_test.go
+++ b/src/encoding/json/stream_test.go
@@ -44,6 +44,9 @@ func TestEncoder(t *testing.T) {
 	for i := 0; i <= len(streamTest); i++ {
 		var buf bytes.Buffer
 		enc := NewEncoder(&buf)
+		// Check that enc.SetIndent("", "") turns off indentation.
+		enc.SetIndent(">", ".")
+		enc.SetIndent("", "")
 		for j, v := range streamTest[0:i] {
 			if err := enc.Encode(v); err != nil {
 				t.Fatalf("encode #%d: %v", j, err)
@@ -77,7 +80,7 @@ false
 func TestEncoderIndent(t *testing.T) {
 	var buf bytes.Buffer
 	enc := NewEncoder(&buf)
-	enc.Indent(">", ".")
+	enc.SetIndent(">", ".")
 	for _, v := range streamTest {
 		enc.Encode(v)
 	}