diff --git a/encode.go b/encode.go
index e5f6e8a..ea2bc7c 100644
--- a/encode.go
+++ b/encode.go
@@ -43,9 +43,9 @@ func (e *Encoder) EncodeWithOption(v interface{}, optFuncs ...EncodeOptionFunc)
 }
 
 func (e *Encoder) encodeWithOption(ctx *encoder.RuntimeContext, v interface{}, optFuncs ...EncodeOptionFunc) error {
-	initOption(ctx.Option)
+	ctx.Option.Flag = 0
 	if e.enabledHTMLEscape {
-		ctx.Option.HTMLEscape = true
+		ctx.Option.Flag |= encoder.HTMLEscapeOption
 	}
 	for _, optFunc := range optFuncs {
 		optFunc(ctx.Option)
@@ -97,8 +97,8 @@ func (e *Encoder) SetIndent(prefix, indent string) {
 func marshal(v interface{}, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 	ctx := encoder.TakeRuntimeContext()
 
-	initOption(ctx.Option)
-	ctx.Option.HTMLEscape = true
+	ctx.Option.Flag = 0
+	ctx.Option.Flag |= encoder.HTMLEscapeOption
 	for _, optFunc := range optFuncs {
 		optFunc(ctx.Option)
 	}
@@ -124,8 +124,8 @@ func marshal(v interface{}, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 func marshalNoEscape(v interface{}) ([]byte, error) {
 	ctx := encoder.TakeRuntimeContext()
 
-	initOption(ctx.Option)
-	ctx.Option.HTMLEscape = true
+	ctx.Option.Flag = 0
+	ctx.Option.Flag |= encoder.HTMLEscapeOption
 
 	buf, err := encodeNoEscape(ctx, v)
 	if err != nil {
@@ -148,9 +148,8 @@ func marshalNoEscape(v interface{}) ([]byte, error) {
 func marshalIndent(v interface{}, prefix, indent string, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 	ctx := encoder.TakeRuntimeContext()
 
-	initOption(ctx.Option)
-	ctx.Option.HTMLEscape = true
-	ctx.Option.Indent = true
+	ctx.Option.Flag = 0
+	ctx.Option.Flag |= (encoder.HTMLEscapeOption | encoder.IndentOption)
 	for _, optFunc := range optFuncs {
 		optFunc(ctx.Option)
 	}
@@ -255,13 +254,13 @@ func encodeIndent(ctx *encoder.RuntimeContext, v interface{}, prefix, indent str
 }
 
 func encodeRunCode(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
-	if ctx.Option.Debug {
-		if ctx.Option.Colorize {
+	if (ctx.Option.Flag & encoder.DebugOption) != 0 {
+		if (ctx.Option.Flag & encoder.ColorizeOption) != 0 {
 			return vm_color.DebugRun(ctx, b, codeSet)
 		}
 		return vm.DebugRun(ctx, b, codeSet)
 	}
-	if ctx.Option.Colorize {
+	if (ctx.Option.Flag & encoder.ColorizeOption) != 0 {
 		return vm_color.Run(ctx, b, codeSet)
 	}
 	return vm.Run(ctx, b, codeSet)
@@ -270,22 +269,14 @@ func encodeRunCode(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.Opcod
 func encodeRunIndentCode(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet, prefix, indent string) ([]byte, error) {
 	ctx.Prefix = []byte(prefix)
 	ctx.IndentStr = []byte(indent)
-	if ctx.Option.Debug {
-		if ctx.Option.Colorize {
+	if (ctx.Option.Flag & encoder.DebugOption) != 0 {
+		if (ctx.Option.Flag & encoder.ColorizeOption) != 0 {
 			return vm_color_indent.DebugRun(ctx, b, codeSet)
 		}
 		return vm_indent.DebugRun(ctx, b, codeSet)
 	}
-	if ctx.Option.Colorize {
+	if (ctx.Option.Flag & encoder.ColorizeOption) != 0 {
 		return vm_color_indent.Run(ctx, b, codeSet)
 	}
 	return vm_indent.Run(ctx, b, codeSet)
 }
-
-func initOption(opt *EncodeOption) {
-	opt.HTMLEscape = false
-	opt.Indent = false
-	opt.UnorderedMap = false
-	opt.Debug = false
-	opt.Colorize = false
-}
diff --git a/internal/cmd/generator/vm.go.tmpl b/internal/cmd/generator/vm.go.tmpl
index 0f8ca7a..2091ba1 100644
--- a/internal/cmd/generator/vm.go.tmpl
+++ b/internal/cmd/generator/vm.go.tmpl
@@ -14,7 +14,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 	ptrOffset := uintptr(0)
 	ctxptr := ctx.Ptr()
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
@@ -370,7 +370,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			store(ctxptr, code.ElemIdx, 0)
 			store(ctxptr, code.Length, uintptr(mlen))
 			store(ctxptr, code.MapIter, uintptr(iter))
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendMapKeyIndent(ctx, code.Next, b)
 			} else {
 				mapCtx := encoder.NewMapContext(mlen)
@@ -385,7 +385,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			idx := load(ctxptr, code.ElemIdx)
 			length := load(ctxptr, code.Length)
 			idx++
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				if idx < length {
 					b = appendMapKeyIndent(ctx, code, b)
 					store(ctxptr, code.ElemIdx, idx)
@@ -414,7 +414,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				}
 			}
 		case encoder.OpMapValue:
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendColon(ctx, b)
 			} else {
 				ptr := load(ctxptr, code.End.MapPos)
diff --git a/internal/encoder/compiler.go b/internal/encoder/compiler.go
index ea05f3f..f9937a4 100644
--- a/internal/encoder/compiler.go
+++ b/internal/encoder/compiler.go
@@ -1456,7 +1456,7 @@ func compileStruct(ctx *compileContext, isPtr bool) (*Opcode, error) {
 		}
 		var key string
 		if ctx.escapeKey {
-			rctx := &RuntimeContext{Option: &Option{HTMLEscape: true}}
+			rctx := &RuntimeContext{Option: &Option{Flag: HTMLEscapeOption}}
 			key = fmt.Sprintf(`%s:`, string(AppendString(rctx, []byte{}, tag.Key)))
 		} else {
 			key = fmt.Sprintf(`"%s":`, tag.Key)
diff --git a/internal/encoder/encoder.go b/internal/encoder/encoder.go
index 0a737c9..5368ce3 100644
--- a/internal/encoder/encoder.go
+++ b/internal/encoder/encoder.go
@@ -375,7 +375,7 @@ func AppendMarshalJSON(ctx *RuntimeContext, code *Opcode, b []byte, v interface{
 	}
 	marshalBuf := ctx.MarshalBuf[:0]
 	marshalBuf = append(append(marshalBuf, bb...), nul)
-	compactedBuf, err := compact(b, marshalBuf, ctx.Option.HTMLEscape)
+	compactedBuf, err := compact(b, marshalBuf, (ctx.Option.Flag&HTMLEscapeOption) != 0)
 	if err != nil {
 		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
 	}
@@ -410,7 +410,7 @@ func AppendMarshalJSONIndent(ctx *RuntimeContext, code *Opcode, b []byte, v inte
 		marshalBuf,
 		string(ctx.Prefix)+strings.Repeat(string(ctx.IndentStr), int(ctx.BaseIndent+code.Indent)),
 		string(ctx.IndentStr),
-		ctx.Option.HTMLEscape,
+		(ctx.Option.Flag&HTMLEscapeOption) != 0,
 	)
 	if err != nil {
 		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
diff --git a/internal/encoder/option.go b/internal/encoder/option.go
index 1c947cd..3cc3502 100644
--- a/internal/encoder/option.go
+++ b/internal/encoder/option.go
@@ -1,12 +1,18 @@
 package encoder
 
+type OptionFlag uint8
+
+const (
+	HTMLEscapeOption OptionFlag = 1 << iota
+	IndentOption
+	UnorderedMapOption
+	DebugOption
+	ColorizeOption
+)
+
 type Option struct {
-	HTMLEscape   bool
-	Indent       bool
-	UnorderedMap bool
-	Debug        bool
-	Colorize     bool
-	ColorScheme  *ColorScheme
+	Flag        OptionFlag
+	ColorScheme *ColorScheme
 }
 
 type EncodeFormat struct {
diff --git a/internal/encoder/string.go b/internal/encoder/string.go
index da2c26d..a699dba 100644
--- a/internal/encoder/string.go
+++ b/internal/encoder/string.go
@@ -406,7 +406,7 @@ func stringToUint64Slice(s string) []uint64 {
 }
 
 func AppendString(ctx *RuntimeContext, buf []byte, s string) []byte {
-	if !ctx.Option.HTMLEscape {
+	if ctx.Option.Flag&HTMLEscapeOption == 0 {
 		return appendString(buf, s)
 	}
 	valLen := len(s)
diff --git a/internal/encoder/vm/debug_vm.go b/internal/encoder/vm/debug_vm.go
index 7bd8d12..05509fe 100644
--- a/internal/encoder/vm/debug_vm.go
+++ b/internal/encoder/vm/debug_vm.go
@@ -9,7 +9,7 @@ import (
 func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
 	defer func() {
 		var code *encoder.Opcode
-		if ctx.Option.HTMLEscape {
+		if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 			code = codeSet.EscapeKeyCode
 		} else {
 			code = codeSet.NoescapeKeyCode
diff --git a/internal/encoder/vm/vm.go b/internal/encoder/vm/vm.go
index 0f8ca7a..2091ba1 100644
--- a/internal/encoder/vm/vm.go
+++ b/internal/encoder/vm/vm.go
@@ -14,7 +14,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 	ptrOffset := uintptr(0)
 	ctxptr := ctx.Ptr()
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
@@ -370,7 +370,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			store(ctxptr, code.ElemIdx, 0)
 			store(ctxptr, code.Length, uintptr(mlen))
 			store(ctxptr, code.MapIter, uintptr(iter))
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendMapKeyIndent(ctx, code.Next, b)
 			} else {
 				mapCtx := encoder.NewMapContext(mlen)
@@ -385,7 +385,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			idx := load(ctxptr, code.ElemIdx)
 			length := load(ctxptr, code.Length)
 			idx++
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				if idx < length {
 					b = appendMapKeyIndent(ctx, code, b)
 					store(ctxptr, code.ElemIdx, idx)
@@ -414,7 +414,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				}
 			}
 		case encoder.OpMapValue:
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendColon(ctx, b)
 			} else {
 				ptr := load(ctxptr, code.End.MapPos)
diff --git a/internal/encoder/vm_color/debug_vm.go b/internal/encoder/vm_color/debug_vm.go
index 5d6db1e..6a6a33d 100644
--- a/internal/encoder/vm_color/debug_vm.go
+++ b/internal/encoder/vm_color/debug_vm.go
@@ -8,7 +8,7 @@ import (
 
 func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
diff --git a/internal/encoder/vm_color/vm.go b/internal/encoder/vm_color/vm.go
index e045f68..0ac3179 100644
--- a/internal/encoder/vm_color/vm.go
+++ b/internal/encoder/vm_color/vm.go
@@ -14,7 +14,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 	ptrOffset := uintptr(0)
 	ctxptr := ctx.Ptr()
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
@@ -370,7 +370,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			store(ctxptr, code.ElemIdx, 0)
 			store(ctxptr, code.Length, uintptr(mlen))
 			store(ctxptr, code.MapIter, uintptr(iter))
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendMapKeyIndent(ctx, code.Next, b)
 			} else {
 				mapCtx := encoder.NewMapContext(mlen)
@@ -385,7 +385,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			idx := load(ctxptr, code.ElemIdx)
 			length := load(ctxptr, code.Length)
 			idx++
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				if idx < length {
 					b = appendMapKeyIndent(ctx, code, b)
 					store(ctxptr, code.ElemIdx, idx)
@@ -414,7 +414,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				}
 			}
 		case encoder.OpMapValue:
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendColon(ctx, b)
 			} else {
 				ptr := load(ctxptr, code.End.MapPos)
diff --git a/internal/encoder/vm_color_indent/debug_vm.go b/internal/encoder/vm_color_indent/debug_vm.go
index ab905d0..a68bbf6 100644
--- a/internal/encoder/vm_color_indent/debug_vm.go
+++ b/internal/encoder/vm_color_indent/debug_vm.go
@@ -8,7 +8,7 @@ import (
 
 func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
diff --git a/internal/encoder/vm_color_indent/vm.go b/internal/encoder/vm_color_indent/vm.go
index 8bf24bb..cd619ca 100644
--- a/internal/encoder/vm_color_indent/vm.go
+++ b/internal/encoder/vm_color_indent/vm.go
@@ -14,7 +14,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 	ptrOffset := uintptr(0)
 	ctxptr := ctx.Ptr()
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
@@ -370,7 +370,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			store(ctxptr, code.ElemIdx, 0)
 			store(ctxptr, code.Length, uintptr(mlen))
 			store(ctxptr, code.MapIter, uintptr(iter))
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendMapKeyIndent(ctx, code.Next, b)
 			} else {
 				mapCtx := encoder.NewMapContext(mlen)
@@ -385,7 +385,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			idx := load(ctxptr, code.ElemIdx)
 			length := load(ctxptr, code.Length)
 			idx++
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				if idx < length {
 					b = appendMapKeyIndent(ctx, code, b)
 					store(ctxptr, code.ElemIdx, idx)
@@ -414,7 +414,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				}
 			}
 		case encoder.OpMapValue:
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendColon(ctx, b)
 			} else {
 				ptr := load(ctxptr, code.End.MapPos)
diff --git a/internal/encoder/vm_indent/debug_vm.go b/internal/encoder/vm_indent/debug_vm.go
index b3822f5..4cfd17a 100644
--- a/internal/encoder/vm_indent/debug_vm.go
+++ b/internal/encoder/vm_indent/debug_vm.go
@@ -8,7 +8,7 @@ import (
 
 func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
diff --git a/internal/encoder/vm_indent/vm.go b/internal/encoder/vm_indent/vm.go
index c19b254..a4eb235 100644
--- a/internal/encoder/vm_indent/vm.go
+++ b/internal/encoder/vm_indent/vm.go
@@ -14,7 +14,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 	ptrOffset := uintptr(0)
 	ctxptr := ctx.Ptr()
 	var code *encoder.Opcode
-	if ctx.Option.HTMLEscape {
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
 		code = codeSet.EscapeKeyCode
 	} else {
 		code = codeSet.NoescapeKeyCode
@@ -370,7 +370,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			store(ctxptr, code.ElemIdx, 0)
 			store(ctxptr, code.Length, uintptr(mlen))
 			store(ctxptr, code.MapIter, uintptr(iter))
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendMapKeyIndent(ctx, code.Next, b)
 			} else {
 				mapCtx := encoder.NewMapContext(mlen)
@@ -385,7 +385,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 			idx := load(ctxptr, code.ElemIdx)
 			length := load(ctxptr, code.Length)
 			idx++
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				if idx < length {
 					b = appendMapKeyIndent(ctx, code, b)
 					store(ctxptr, code.ElemIdx, idx)
@@ -414,7 +414,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				}
 			}
 		case encoder.OpMapValue:
-			if ctx.Option.UnorderedMap {
+			if (ctx.Option.Flag & encoder.UnorderedMapOption) != 0 {
 				b = appendColon(ctx, b)
 			} else {
 				ptr := load(ctxptr, code.End.MapPos)
diff --git a/option.go b/option.go
index 40d25c7..444ffd0 100644
--- a/option.go
+++ b/option.go
@@ -10,19 +10,19 @@ type EncodeOptionFunc func(*EncodeOption)
 
 func UnorderedMap() EncodeOptionFunc {
 	return func(opt *EncodeOption) {
-		opt.UnorderedMap = true
+		opt.Flag |= encoder.UnorderedMapOption
 	}
 }
 
 func Debug() EncodeOptionFunc {
 	return func(opt *EncodeOption) {
-		opt.Debug = true
+		opt.Flag |= encoder.DebugOption
 	}
 }
 
 func Colorize(scheme *ColorScheme) EncodeOptionFunc {
 	return func(opt *EncodeOption) {
-		opt.Colorize = true
+		opt.Flag |= encoder.ColorizeOption
 		opt.ColorScheme = scheme
 	}
 }