diff --git a/monitor_darwin.go b/monitor_darwin.go
index 032f329..42f9c36 100644
--- a/monitor_darwin.go
+++ b/monitor_darwin.go
@@ -42,7 +42,7 @@ func (m *networkUpdateMonitor) loopUpdate() {
 		select {
 		case <-m.done:
 			return
-		case <-time.After(time.Second):
+		default:
 		}
 		err := m.loopUpdate0()
 		if err != nil {
@@ -67,7 +67,16 @@ func (m *networkUpdateMonitor) loopUpdate1(routeSocketFile *os.File) {
 	defer routeSocketFile.Close()
 	buffer := buf.NewPacket()
 	defer buffer.Release()
+	done := make(chan struct{})
+	go func() {
+		select {
+		case <-m.done:
+			routeSocketFile.Close()
+		case <-done:
+		}
+	}()
 	n, err := routeSocketFile.Read(buffer.FreeBytes())
+	close(done)
 	if err != nil {
 		return
 	}
@@ -92,57 +101,59 @@ func (m *networkUpdateMonitor) Close() error {
 }
 
 func (m *defaultInterfaceMonitor) checkUpdate() error {
-	ribMessage, err := route.FetchRIB(unix.AF_UNSPEC, route.RIBTypeRoute, 0)
-	if err != nil {
-		return err
-	}
-	routeMessages, err := route.ParseRIB(route.RIBTypeRoute, ribMessage)
-	if err != nil {
-		return err
-	}
-	var defaultInterface *net.Interface
-	for _, rawRouteMessage := range routeMessages {
-		routeMessage := rawRouteMessage.(*route.RouteMessage)
-		if len(routeMessage.Addrs) <= unix.RTAX_NETMASK {
-			continue
-		}
-		destination, isIPv4Destination := routeMessage.Addrs[unix.RTAX_DST].(*route.Inet4Addr)
-		if !isIPv4Destination {
-			continue
-		}
-		if destination.IP != netip.IPv4Unspecified().As4() {
-			continue
-		}
-		mask, isIPv4Mask := routeMessage.Addrs[unix.RTAX_NETMASK].(*route.Inet4Addr)
-		if !isIPv4Mask {
-			continue
-		}
-		ones, _ := net.IPMask(mask.IP[:]).Size()
-		if ones != 0 {
-			continue
-		}
-		routeInterface, err := net.InterfaceByIndex(routeMessage.Index)
+	var (
+		defaultInterface *net.Interface
+		err              error
+	)
+	if m.options.UnderNetworkExtension {
+		defaultInterface, err = getDefaultInterfaceBySocket()
 		if err != nil {
 			return err
 		}
-		if routeMessage.Flags&unix.RTF_UP == 0 {
-			continue
+	} else {
+		ribMessage, err := route.FetchRIB(unix.AF_UNSPEC, route.RIBTypeRoute, 0)
+		if err != nil {
+			return err
 		}
-		if routeMessage.Flags&unix.RTF_GATEWAY == 0 {
-			continue
+		routeMessages, err := route.ParseRIB(route.RIBTypeRoute, ribMessage)
+		if err != nil {
+			return err
 		}
-		if routeMessage.Flags&unix.RTF_IFSCOPE != 0 {
-			// continue
-		}
-		defaultInterface = routeInterface
-		break
-	}
-	if defaultInterface == nil {
-		if m.options.UnderNetworkExtension {
-			defaultInterface, err = getDefaultInterfaceBySocket()
+		for _, rawRouteMessage := range routeMessages {
+			routeMessage := rawRouteMessage.(*route.RouteMessage)
+			if len(routeMessage.Addrs) <= unix.RTAX_NETMASK {
+				continue
+			}
+			destination, isIPv4Destination := routeMessage.Addrs[unix.RTAX_DST].(*route.Inet4Addr)
+			if !isIPv4Destination {
+				continue
+			}
+			if destination.IP != netip.IPv4Unspecified().As4() {
+				continue
+			}
+			mask, isIPv4Mask := routeMessage.Addrs[unix.RTAX_NETMASK].(*route.Inet4Addr)
+			if !isIPv4Mask {
+				continue
+			}
+			ones, _ := net.IPMask(mask.IP[:]).Size()
+			if ones != 0 {
+				continue
+			}
+			routeInterface, err := net.InterfaceByIndex(routeMessage.Index)
 			if err != nil {
 				return err
 			}
+			if routeMessage.Flags&unix.RTF_UP == 0 {
+				continue
+			}
+			if routeMessage.Flags&unix.RTF_GATEWAY == 0 {
+				continue
+			}
+			if routeMessage.Flags&unix.RTF_IFSCOPE != 0 {
+				// continue
+			}
+			defaultInterface = routeInterface
+			break
 		}
 	}
 	if defaultInterface == nil {
diff --git a/monitor_shared.go b/monitor_shared.go
index 66c8f1a..f286657 100644
--- a/monitor_shared.go
+++ b/monitor_shared.go
@@ -6,7 +6,6 @@ import (
 	"errors"
 	"net"
 	"net/netip"
-	"runtime"
 	"sync"
 	"time"
 
@@ -44,6 +43,7 @@ type defaultInterfaceMonitor struct {
 	defaultInterfaceIndex int
 	androidVPNEnabled     bool
 	networkMonitor        NetworkUpdateMonitor
+	checkUpdateTimer      *time.Timer
 	element               *list.Element[NetworkUpdateCallback]
 	access                sync.Mutex
 	callbacks             list.List[DefaultInterfaceUpdateCallback]
@@ -72,9 +72,13 @@ func (m *defaultInterfaceMonitor) Start() error {
 }
 
 func (m *defaultInterfaceMonitor) delayCheckUpdate() {
-	if runtime.GOOS == "android" {
-		time.Sleep(time.Second)
+	if m.checkUpdateTimer != nil {
+		m.checkUpdateTimer.Stop()
 	}
+	m.checkUpdateTimer = time.AfterFunc(time.Second, m.postCheckUpdate)
+}
+
+func (m *defaultInterfaceMonitor) postCheckUpdate() {
 	err := m.updateInterfaces()
 	if err != nil {
 		m.logger.Error("update interfaces: ", err)