diff --git a/listener/tun/ipstack/system/mars/nat/udp.go b/listener/tun/ipstack/system/mars/nat/udp.go
index b28614a5..4e7a4f9e 100644
--- a/listener/tun/ipstack/system/mars/nat/udp.go
+++ b/listener/tun/ipstack/system/mars/nat/udp.go
@@ -74,8 +74,8 @@ func (u *UDP) WriteTo(buf []byte, local net.Addr, remote net.Addr) (int, error)
 	srcIP, _ := netip.AddrFromSlice(srcAddr.IP)
 	dstIp, _ := netip.AddrFromSlice(dstAddr.IP)
 
-	srcAddrPort := netip.AddrPortFrom(srcIP, uint16(srcAddr.Port))
-	dstAddrPort := netip.AddrPortFrom(dstIp, uint16(dstAddr.Port))
+	srcAddrPort := netip.AddrPortFrom(srcIP.Unmap(), uint16(srcAddr.Port))
+	dstAddrPort := netip.AddrPortFrom(dstIp.Unmap(), uint16(dstAddr.Port))
 
 	if !srcAddrPort.Addr().Is4() || !dstAddrPort.Addr().Is4() {
 		return 0, net.InvalidAddrError("invalid ip version")
diff --git a/listener/tun/ipstack/system/stack.go b/listener/tun/ipstack/system/stack.go
index 01e4c952..ad3f465d 100644
--- a/listener/tun/ipstack/system/stack.go
+++ b/listener/tun/ipstack/system/stack.go
@@ -176,7 +176,7 @@ func New(device device.Device, dnsHijack []netip.AddrPort, tunAddress netip.Pref
 				local: lAddr,
 				data:  raw,
 				writeBack: func(b []byte, addr net.Addr) (int, error) {
-					return stack.UDP().WriteTo(b, addr, lAddr)
+					return stack.UDP().WriteTo(b, rAddr, lAddr)
 				},
 				drop: func() {
 					pool.Put(buf)