diff --git a/tunnel/connection.go b/tunnel/connection.go
index cf024c7..cf37114 100644
--- a/tunnel/connection.go
+++ b/tunnel/connection.go
@@ -44,7 +44,7 @@ func handleUDPToLocal(packet C.UDPPacket, pc net.PacketConn, key string, oAddr,
 		fromUDPAddr := from.(*net.UDPAddr)
 		if fAddr.IsValid() {
 			fromAddr, _ := netip.AddrFromSlice(fromUDPAddr.IP)
-			fromAddr.Unmap()
+			fromAddr = fromAddr.Unmap()
 			if oAddr == fromAddr {
 				fromUDPAddr.IP = fAddr.AsSlice()
 			}