diff --git a/tun/netstack/tun.go b/tun/netstack/tun.go
index a0b212a..fa15f53 100644
--- a/tun/netstack/tun.go
+++ b/tun/netstack/tun.go
@@ -65,8 +65,13 @@ func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int) (tun.Device,
 		dnsServers:     dnsServers,
 		mtu:            mtu,
 	}
+	sackEnabledOpt := tcpip.TCPSACKEnabled(true) // TCP SACK is disabled by default
+	tcpipErr := dev.stack.SetTransportProtocolOption(tcp.ProtocolNumber, &sackEnabledOpt)
+	if tcpipErr != nil {
+		return nil, nil, fmt.Errorf("could not enable TCP SACK: %v", tcpipErr)
+	}
 	dev.ep.AddNotify(dev)
-	tcpipErr := dev.stack.CreateNIC(1, dev.ep)
+	tcpipErr = dev.stack.CreateNIC(1, dev.ep)
 	if tcpipErr != nil {
 		return nil, nil, fmt.Errorf("CreateNIC: %v", tcpipErr)
 	}