diff --git a/decor/on_complete.go b/decor/on_complete.go
index 0a3897b..403b58c 100644
--- a/decor/on_complete.go
+++ b/decor/on_complete.go
@@ -1,29 +1,20 @@
 package decor
 
 var (
-	_ Decorator = (*onCompleteWrapper)(nil)
-	_ Wrapper   = (*onCompleteWrapper)(nil)
+	_ Decorator = onCompleteWrapper{}
+	_ Wrapper   = onCompleteWrapper{}
 )
 
-// OnComplete returns decorator, which wraps provided decorator with
-// sole purpose to display provided message on complete event.
+// OnComplete wrap decorator.
+// Displays provided message on complete event.
 //
 //	`decorator` Decorator to wrap
-//
-//	`message` message to display on complete event
+//	`message` message to display
 func OnComplete(decorator Decorator, message string) Decorator {
 	if decorator == nil {
 		return nil
 	}
-	d := &onCompleteWrapper{
-		Decorator: decorator,
-		msg:       message,
-	}
-	if md, ok := decorator.(*mergeDecorator); ok {
-		d.Decorator, md.Decorator = md.Decorator, d
-		return md
-	}
-	return d
+	return onCompleteWrapper{decorator, message}
 }
 
 type onCompleteWrapper struct {
@@ -31,13 +22,13 @@
 	msg string
 }
 
-func (d *onCompleteWrapper) Decor(s Statistics) string {
+func (d onCompleteWrapper) Decor(s Statistics) (string, int) {
 	if s.Completed {
-		return d.GetConf().FormatMsg(d.msg)
+		return d.Format(d.msg)
 	}
 	return d.Decorator.Decor(s)
 }
 
-func (d *onCompleteWrapper) Unwrap() Decorator {
+func (d onCompleteWrapper) Unwrap() Decorator {
 	return d.Decorator
 }