diff --git a/system.go b/system.go
index a857b3a..e3e77eb 100644
--- a/system.go
+++ b/system.go
@@ -402,7 +402,7 @@ func (s *System) processIPv6UDP(packet clashtcpip.IPv6Packet, header clashtcpip.
 
 func (s *System) processIPv4ICMP(packet clashtcpip.IPv4Packet, header clashtcpip.ICMPPacket) error {
 	if s.router != nil {
-		routeSession := RouteSession{4, syscall.IPPROTO_ICMP, netip.AddrPortFrom(packet.SourceIP(), 0), netip.AddrPortFrom(packet.DestinationIP(), 0)}
+		routeSession := RouteSession{4, clashtcpip.ICMP, netip.AddrPortFrom(packet.SourceIP(), 0), netip.AddrPortFrom(packet.DestinationIP(), 0)}
 		action := s.routeMapping.Lookup(routeSession, func() RouteAction {
 			return s.router.RouteConnection(routeSession, &systemICMPDirectPacketWriter4{s.tun, packet.SourceIP()})
 		})
@@ -430,7 +430,7 @@ func (s *System) processIPv4ICMP(packet clashtcpip.IPv4Packet, header clashtcpip
 
 func (s *System) processIPv6ICMP(packet clashtcpip.IPv6Packet, header clashtcpip.ICMPv6Packet) error {
 	if s.router != nil {
-		routeSession := RouteSession{6, syscall.IPPROTO_ICMPV6, netip.AddrPortFrom(packet.SourceIP(), 0), netip.AddrPortFrom(packet.DestinationIP(), 0)}
+		routeSession := RouteSession{6, clashtcpip.ICMPv6, netip.AddrPortFrom(packet.SourceIP(), 0), netip.AddrPortFrom(packet.DestinationIP(), 0)}
 		action := s.routeMapping.Lookup(routeSession, func() RouteAction {
 			return s.router.RouteConnection(routeSession, &systemICMPDirectPacketWriter6{s.tun, packet.SourceIP()})
 		})