diff --git a/route/router.go b/route/router.go
index 484216ee..54f3ac51 100644
--- a/route/router.go
+++ b/route/router.go
@@ -1121,6 +1121,9 @@ func (r *Router) AutoDetectInterfaceFunc() control.Func {
 	if r.platformInterface != nil && r.platformInterface.UsePlatformAutoDetectInterfaceControl() {
 		return r.platformInterface.AutoDetectInterfaceControl()
 	} else {
+		if r.interfaceMonitor == nil {
+			return nil
+		}
 		return control.BindToInterfaceFunc(r.InterfaceFinder(), func(network string, address string) (interfaceName string, interfaceIndex int, err error) {
 			remoteAddr := M.ParseSocksaddr(address).Addr
 			if C.IsLinux {