diff --git a/signal/README.md b/signal/README.md
index 74d2906d..ccf99804 100644
--- a/signal/README.md
+++ b/signal/README.md
@@ -44,7 +44,9 @@ func (h *exampleHandler) Handle(sig os.Signal) {
 	println("exampleHandler signal:", sig)
 }
 
-type example2Handler struct{}
+type example2Handler struct{
+	signal.AsyncFeature // async feature
+}
 
 func (h *example2Handler) Listen() []os.Signal {
 	return []os.Signal{syscall.SIGUSR1}
diff --git a/signal/handler.go b/signal/handler.go
index 5195d4a3..dd8ae6d1 100644
--- a/signal/handler.go
+++ b/signal/handler.go
@@ -9,6 +9,12 @@ type Handler interface {
 	Handle(os.Signal)
 }
 
-type AsyncFeature interface {
+type asyncFeature interface {
 	Async() bool
 }
+
+type AsyncFeature struct{}
+
+func (*AsyncFeature) Async() bool {
+	return true
+}
diff --git a/signal/server.go b/signal/server.go
index 5389f1a6..53370400 100644
--- a/signal/server.go
+++ b/signal/server.go
@@ -79,8 +79,8 @@ func (s *Server) Start(ctx context.Context) error {
 		case sig := <-ch:
 			if hs, ok := handlers[sig]; ok {
 				for _, h := range hs {
-					// if Support AsyncFeature
-					if async, ok := h.(AsyncFeature); ok && async.Async() {
+					// if Support asyncFeature
+					if async, ok := h.(asyncFeature); ok && async.Async() {
 						go s.handle(sig, h)
 					} else {
 						s.handle(sig, h)