diff --git a/encode.go b/encode.go
index 2247322..05b15d9 100644
--- a/encode.go
+++ b/encode.go
@@ -19,7 +19,6 @@ type Encoder struct {
 	enabledHTMLEscape              bool
 	prefix                         []byte
 	indentStr                      []byte
-	indent                         int
 	structTypeToCompiledCode       map[uintptr]*compiledCode
 	structTypeToCompiledIndentCode map[uintptr]*compiledCode
 }
@@ -123,7 +122,6 @@ func (e *Encoder) release() {
 
 func (e *Encoder) reset() {
 	e.buf = e.buf[:0]
-	e.indent = 0
 	e.enabledHTMLEscape = true
 	e.enabledIndent = false
 }
diff --git a/encode_compile.go b/encode_compile.go
index 229c485..b0e8800 100644
--- a/encode_compile.go
+++ b/encode_compile.go
@@ -10,13 +10,13 @@ func (e *Encoder) compileHead(ctx *encodeCompileContext) (*opcode, error) {
 	typ := ctx.typ
 	switch {
 	case typ.Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalJSON), nil
 	case rtype_ptrTo(typ).Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalJSON), nil
 	case typ.Implements(marshalTextType):
-		return newOpCode(opMarshalText, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalText), nil
 	case rtype_ptrTo(typ).Implements(marshalTextType):
-		return newOpCode(opMarshalText, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalText), nil
 	}
 	isPtr := false
 	if typ.Kind() == reflect.Ptr {
@@ -49,13 +49,13 @@ func (e *Encoder) compile(ctx *encodeCompileContext) (*opcode, error) {
 	typ := ctx.typ
 	switch {
 	case typ.Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalJSON), nil
 	case rtype_ptrTo(typ).Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalJSON), nil
 	case typ.Implements(marshalTextType):
-		return newOpCode(opMarshalText, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalText), nil
 	case rtype_ptrTo(typ).Implements(marshalTextType):
-		return newOpCode(opMarshalText, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalText), nil
 	}
 	switch typ.Kind() {
 	case reflect.Ptr:
@@ -112,13 +112,13 @@ func (e *Encoder) compileKey(ctx *encodeCompileContext) (*opcode, error) {
 	typ := ctx.typ
 	switch {
 	case typ.Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalJSON), nil
 	case rtype_ptrTo(typ).Implements(marshalJSONType):
-		return newOpCode(opMarshalJSON, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalJSON), nil
 	case typ.Implements(marshalTextType):
-		return newOpCode(opMarshalText, typ, e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx, opMarshalText), nil
 	case rtype_ptrTo(typ).Implements(marshalTextType):
-		return newOpCode(opMarshalText, rtype_ptrTo(typ), e.indent, newEndOp(e.indent)), nil
+		return newOpCode(ctx.withType(rtype_ptrTo(typ)), opMarshalText), nil
 	}
 	switch typ.Kind() {
 	case reflect.Ptr:
@@ -132,13 +132,12 @@ func (e *Encoder) compileKey(ctx *encodeCompileContext) (*opcode, error) {
 }
 
 func (e *Encoder) optimizeStructFieldPtrHead(ctx *encodeCompileContext, code *opcode) *opcode {
-	typ := ctx.typ
 	ptrHeadOp := code.op.headToPtrHead()
 	if code.op != ptrHeadOp {
 		code.op = ptrHeadOp
 		return code
 	}
-	return newOpCode(opPtr, typ, e.indent, code)
+	return newOpCodeWithNext(ctx, opPtr, code)
 }
 
 func (e *Encoder) compilePtr(ctx *encodeCompileContext) (*opcode, error) {
@@ -150,63 +149,63 @@ func (e *Encoder) compilePtr(ctx *encodeCompileContext) (*opcode, error) {
 }
 
 func (e *Encoder) compileInt(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opInt, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opInt), nil
 }
 
 func (e *Encoder) compileInt8(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opInt8, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opInt8), nil
 }
 
 func (e *Encoder) compileInt16(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opInt16, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opInt16), nil
 }
 
 func (e *Encoder) compileInt32(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opInt32, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opInt32), nil
 }
 
 func (e *Encoder) compileInt64(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opInt64, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opInt64), nil
 }
 
 func (e *Encoder) compileUint(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opUint, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opUint), nil
 }
 
 func (e *Encoder) compileUint8(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opUint8, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opUint8), nil
 }
 
 func (e *Encoder) compileUint16(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opUint16, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opUint16), nil
 }
 
 func (e *Encoder) compileUint32(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opUint32, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opUint32), nil
 }
 
 func (e *Encoder) compileUint64(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opUint64, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opUint64), nil
 }
 
 func (e *Encoder) compileFloat32(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opFloat32, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opFloat32), nil
 }
 
 func (e *Encoder) compileFloat64(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opFloat64, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opFloat64), nil
 }
 
 func (e *Encoder) compileString(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opString, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opString), nil
 }
 
 func (e *Encoder) compileBool(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opBool, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opBool), nil
 }
 
 func (e *Encoder) compileBytes(ctx *encodeCompileContext) (*opcode, error) {
-	return newOpCode(opBytes, ctx.typ, e.indent, newEndOp(e.indent)), nil
+	return newOpCode(ctx, opBytes), nil
 }
 
 func (e *Encoder) compileInterface(ctx *encodeCompileContext) (*opcode, error) {
@@ -214,8 +213,8 @@ func (e *Encoder) compileInterface(ctx *encodeCompileContext) (*opcode, error) {
 		opcodeHeader: &opcodeHeader{
 			op:     opInterface,
 			typ:    ctx.typ,
-			indent: e.indent,
-			next:   newEndOp(e.indent),
+			indent: ctx.indent,
+			next:   newEndOp(ctx),
 		},
 		root: ctx.root,
 	})), nil
@@ -226,10 +225,7 @@ func (e *Encoder) compileSlice(ctx *encodeCompileContext) (*opcode, error) {
 	elem := ctx.typ.Elem()
 	size := elem.Size()
 
-	e.indent++
-	code, err := e.compile(ctx.withType(ctx.typ.Elem()))
-	e.indent--
-
+	code, err := e.compile(ctx.withType(ctx.typ.Elem()).incIndent())
 	if err != nil {
 		return nil, err
 	}
@@ -238,15 +234,15 @@ func (e *Encoder) compileSlice(ctx *encodeCompileContext) (*opcode, error) {
 	//             ^        |
 	//             |________|
 
-	header := newSliceHeaderCode(e.indent)
+	header := newSliceHeaderCode(ctx.indent)
 	elemCode := &sliceElemCode{
 		opcodeHeader: &opcodeHeader{
 			op:     opSliceElem,
-			indent: e.indent,
+			indent: ctx.indent,
 		},
 		size: size,
 	}
-	end := newOpCode(opSliceEnd, nil, e.indent, newEndOp(e.indent))
+	end := newOpCode(ctx, opSliceEnd)
 	if ctx.withIndent {
 		if ctx.root {
 			header.op = opRootSliceHeadIndent
@@ -274,10 +270,7 @@ func (e *Encoder) compileArray(ctx *encodeCompileContext) (*opcode, error) {
 	alen := typ.Len()
 	size := elem.Size()
 
-	e.indent++
-	code, err := e.compile(ctx.withType(elem))
-	e.indent--
-
+	code, err := e.compile(ctx.withType(elem).incIndent())
 	if err != nil {
 		return nil, err
 	}
@@ -285,7 +278,7 @@ func (e *Encoder) compileArray(ctx *encodeCompileContext) (*opcode, error) {
 	//             ^        |
 	//             |________|
 
-	header := newArrayHeaderCode(e.indent, alen)
+	header := newArrayHeaderCode(ctx.indent, alen)
 	elemCode := &arrayElemCode{
 		opcodeHeader: &opcodeHeader{
 			op: opArrayElem,
@@ -293,7 +286,7 @@ func (e *Encoder) compileArray(ctx *encodeCompileContext) (*opcode, error) {
 		len:  uintptr(alen),
 		size: size,
 	}
-	end := newOpCode(opArrayEnd, nil, e.indent, newEndOp(e.indent))
+	end := newOpCode(ctx, opArrayEnd)
 
 	if ctx.withIndent {
 		header.op = opArrayHeadIndent
@@ -330,7 +323,7 @@ func (e *Encoder) compileMap(ctx *encodeCompileContext, withLoad bool) (*opcode,
 	// header => code => value => code => key => code => value => code => end
 	//                                     ^                       |
 	//                                     |_______________________|
-	e.indent++
+	ctx = ctx.incIndent()
 	typ := ctx.typ
 	keyType := ctx.typ.Key()
 	keyCode, err := e.compileKey(ctx.withType(keyType))
@@ -343,15 +336,15 @@ func (e *Encoder) compileMap(ctx *encodeCompileContext, withLoad bool) (*opcode,
 		return nil, err
 	}
 
-	key := newMapKeyCode(e.indent)
-	value := newMapValueCode(e.indent)
+	key := newMapKeyCode(ctx.indent)
+	value := newMapValueCode(ctx.indent)
 
-	e.indent--
+	ctx = ctx.decIndent()
 
-	header := newMapHeaderCode(typ, withLoad, e.indent)
+	header := newMapHeaderCode(typ, withLoad, ctx.indent)
 	header.key = key
 	header.value = value
-	end := newOpCode(opMapEnd, nil, e.indent, newEndOp(e.indent))
+	end := newOpCode(ctx, opMapEnd)
 
 	if ctx.withIndent {
 		if header.op == opMapHead {
@@ -533,8 +526,8 @@ func (e *Encoder) recursiveCode(ctx *encodeCompileContext, code *compiledCode) *
 		opcodeHeader: &opcodeHeader{
 			op:     opStructFieldRecursive,
 			typ:    ctx.typ,
-			indent: e.indent,
-			next:   newEndOp(e.indent),
+			indent: ctx.indent,
+			next:   newEndOp(ctx),
 		},
 		jmp: code,
 	}))
@@ -793,7 +786,7 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 		code      *opcode
 		prevField *structFieldCode
 	)
-	e.indent++
+	ctx = ctx.incIndent()
 	tags := structTags{}
 	anonymousFields := map[string][]structFieldPair{}
 	for i := 0; i < fieldNum; i++ {
@@ -839,7 +832,7 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 			opcodeHeader: &opcodeHeader{
 				typ:    valueCode.typ,
 				next:   valueCode,
-				indent: e.indent,
+				indent: ctx.indent,
 			},
 			anonymousKey: field.Anonymous,
 			key:          []byte(key),
@@ -860,16 +853,16 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 		}
 		fieldIdx++
 	}
-	e.indent--
+	ctx = ctx.decIndent()
 
 	structEndCode := (*opcode)(unsafe.Pointer(&structFieldCode{
 		opcodeHeader: &opcodeHeader{
 			op:     opStructEnd,
 			typ:    nil,
-			indent: e.indent,
+			indent: ctx.indent,
 		},
 	}))
-	structEndCode.next = newEndOp(e.indent)
+	structEndCode.next = newEndOp(ctx)
 	if ctx.withIndent {
 		structEndCode.op = opStructEndIndent
 	}
@@ -884,7 +877,7 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 			opcodeHeader: &opcodeHeader{
 				op:     opStructFieldHead,
 				typ:    typ,
-				indent: e.indent,
+				indent: ctx.indent,
 			},
 			nextField: structEndCode,
 		}
diff --git a/encode_context.go b/encode_context.go
new file mode 100644
index 0000000..0d25884
--- /dev/null
+++ b/encode_context.go
@@ -0,0 +1,37 @@
+package json
+
+type encodeCompileContext struct {
+	typ         *rtype
+	withIndent  bool
+	root        bool
+	opcodeIndex int
+	indent      int
+}
+
+func (c *encodeCompileContext) context() *encodeCompileContext {
+	return &encodeCompileContext{
+		typ:         c.typ,
+		withIndent:  c.withIndent,
+		root:        c.root,
+		opcodeIndex: c.opcodeIndex,
+		indent:      c.indent,
+	}
+}
+
+func (c *encodeCompileContext) withType(typ *rtype) *encodeCompileContext {
+	ctx := c.context()
+	ctx.typ = typ
+	return ctx
+}
+
+func (c *encodeCompileContext) incIndent() *encodeCompileContext {
+	ctx := c.context()
+	ctx.indent++
+	return ctx
+}
+
+func (c *encodeCompileContext) decIndent() *encodeCompileContext {
+	ctx := c.context()
+	ctx.indent--
+	return ctx
+}
diff --git a/encode_opcode.go b/encode_opcode.go
index 3b78686..b95d1e2 100644
--- a/encode_opcode.go
+++ b/encode_opcode.go
@@ -34,19 +34,30 @@ type opcode struct {
 	*opcodeHeader
 }
 
-func newOpCode(op opType, typ *rtype, indent int, next *opcode) *opcode {
+func newOpCode(ctx *encodeCompileContext, op opType) *opcode {
 	return &opcode{
 		opcodeHeader: &opcodeHeader{
 			op:     op,
-			typ:    typ,
-			indent: indent,
+			typ:    ctx.typ,
+			indent: ctx.indent,
+			next:   newEndOp(ctx),
+		},
+	}
+}
+
+func newOpCodeWithNext(ctx *encodeCompileContext, op opType, next *opcode) *opcode {
+	return &opcode{
+		opcodeHeader: &opcodeHeader{
+			op:     op,
+			typ:    ctx.typ,
+			indent: ctx.indent,
 			next:   next,
 		},
 	}
 }
 
-func newEndOp(indent int) *opcode {
-	return newOpCode(opEnd, nil, indent, nil)
+func newEndOp(ctx *encodeCompileContext) *opcode {
+	return newOpCodeWithNext(ctx, opEnd, nil)
 }
 
 func (c *opcode) beforeLastCode() *opcode {
@@ -547,7 +558,7 @@ func (c *recursiveCode) copy(codeMap map[uintptr]*opcode) *opcode {
 func newRecursiveCode(recursive *recursiveCode) *opcode {
 	code := copyOpcode(recursive.jmp.code)
 	head := (*structFieldCode)(unsafe.Pointer(code))
-	head.end.next = newEndOp(0)
+	head.end.next = newEndOp(&encodeCompileContext{})
 	code.ptr = recursive.ptr
 
 	code.op = code.op.ptrHeadToHead()
diff --git a/encode_vm.go b/encode_vm.go
index 1873cdc..3f8f012 100644
--- a/encode_vm.go
+++ b/encode_vm.go
@@ -109,13 +109,13 @@ func (e *Encoder) run(code *opcode) error {
 			if typ.Kind() == reflect.Ptr {
 				typ = typ.Elem()
 			}
-			e.indent = ifaceCode.indent
 			var c *opcode
 			if typ.Kind() == reflect.Map {
 				code, err := e.compileMap(&encodeCompileContext{
 					typ:        typ,
 					root:       ifaceCode.root,
 					withIndent: e.enabledIndent,
+					indent:     ifaceCode.indent,
 				}, false)
 				if err != nil {
 					return err
@@ -126,6 +126,7 @@ func (e *Encoder) run(code *opcode) error {
 					typ:        typ,
 					root:       ifaceCode.root,
 					withIndent: e.enabledIndent,
+					indent:     ifaceCode.indent,
 				})
 				if err != nil {
 					return err