diff --git a/bar_option.go b/bar_option.go
index b07fb43..024f2e1 100644
--- a/bar_option.go
+++ b/bar_option.go
@@ -11,15 +11,14 @@
 type BarOption func(*bState)
 
 func inspect(decorators []decor.Decorator) (dest []decor.Decorator) {
-	type mergeWrapper interface {
-		MergeUnwrap() []decor.Decorator
-	}
 	for _, decorator := range decorators {
 		if decorator == nil {
 			continue
 		}
-		if mw, ok := decorator.(mergeWrapper); ok {
-			dest = append(dest, mw.MergeUnwrap()...)
+		if d, ok := decorator.(interface {
+			PlaceHolders() []decor.Decorator
+		}); ok {
+			dest = append(dest, d.PlaceHolders()...)
 		}
 		dest = append(dest, decorator)
 	}
diff --git a/decor/merge.go b/decor/merge.go
index aa0fcb9..02b7a93 100644
--- a/decor/merge.go
+++ b/decor/merge.go
@@ -31,7 +31,7 @@
 	md := &mergeDecorator{
 		Decorator:    decorator,
 		wc:           decorator.GetConf(),
-		placeHolders: make([]*placeHolderDecorator, len(placeholders)),
+		placeHolders: make([]Decorator, len(placeholders)),
 	}
 	decorator.SetConf(WC{})
 	for i, wc := range placeholders {
@@ -46,7 +46,7 @@
 type mergeDecorator struct {
 	Decorator
 	wc           WC
-	placeHolders []*placeHolderDecorator
+	placeHolders []Decorator
 }
 
 func (d *mergeDecorator) GetConf() WC {
@@ -57,12 +57,8 @@
 	d.wc = conf.Init()
 }
 
-func (d *mergeDecorator) MergeUnwrap() []Decorator {
-	decorators := make([]Decorator, len(d.placeHolders))
-	for i, ph := range d.placeHolders {
-		decorators[i] = ph
-	}
-	return decorators
+func (d *mergeDecorator) PlaceHolders() []Decorator {
+	return d.placeHolders
 }
 
 func (d *mergeDecorator) Sync() (chan int, bool) {
@@ -82,21 +78,21 @@
 		cellCount++
 	}
 
-	total := runewidth.StringWidth(d.placeHolders[0].FormatMsg(""))
+	total := runewidth.StringWidth(d.placeHolders[0].GetConf().FormatMsg(""))
 	pw := (cellCount - total) / len(d.placeHolders)
 	rem := (cellCount - total) % len(d.placeHolders)
 
 	var diff int
 	for i := 1; i < len(d.placeHolders); i++ {
-		ph := d.placeHolders[i]
+		wc := d.placeHolders[i].GetConf()
 		width := pw - diff
-		if (ph.WC.C & DextraSpace) != 0 {
+		if (wc.C & DextraSpace) != 0 {
 			width--
 			if width < 0 {
 				width = 0
 			}
 		}
-		max := runewidth.StringWidth(ph.FormatMsg(strings.Repeat(" ", width)))
+		max := runewidth.StringWidth(wc.FormatMsg(strings.Repeat(" ", width)))
 		total += max
 		diff = max - pw
 	}