diff --git a/go.mod b/go.mod
index 88bffc4f..a43e390f 100644
--- a/go.mod
+++ b/go.mod
@@ -28,7 +28,7 @@ require (
 	github.com/sagernet/gomobile v0.1.7
 	github.com/sagernet/gvisor v0.0.0-20250325023245-7a9c0f5725fb
 	github.com/sagernet/quic-go v0.52.0-beta.1
-	github.com/sagernet/sing v0.6.12-0.20250718132236-21daaa465e88
+	github.com/sagernet/sing v0.6.12-0.20250720033754-e79b303754a8
 	github.com/sagernet/sing-mux v0.3.2
 	github.com/sagernet/sing-quic v0.5.0-beta.3
 	github.com/sagernet/sing-shadowsocks v0.2.8
diff --git a/go.sum b/go.sum
index 4ca50a46..35bb4d86 100644
--- a/go.sum
+++ b/go.sum
@@ -168,8 +168,8 @@ github.com/sagernet/nftables v0.3.0-beta.4/go.mod h1:OQXAjvjNGGFxaTgVCSTRIhYB5/l
 github.com/sagernet/quic-go v0.52.0-beta.1 h1:hWkojLg64zjV+MJOvJU/kOeWndm3tiEfBLx5foisszs=
 github.com/sagernet/quic-go v0.52.0-beta.1/go.mod h1:OV+V5kEBb8kJS7k29MzDu6oj9GyMc7HA07sE1tedxz4=
 github.com/sagernet/sing v0.6.9/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
-github.com/sagernet/sing v0.6.12-0.20250718132236-21daaa465e88 h1:Wu6hu+JsZ2gsFRJMqGzaZJ4ctGnmNrLGm9ckmotBFOs=
-github.com/sagernet/sing v0.6.12-0.20250718132236-21daaa465e88/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
+github.com/sagernet/sing v0.6.12-0.20250720033754-e79b303754a8 h1:/jJN9VhQA/q12dXUbkTYEnn2tJ0fa/121u3deoClGVg=
+github.com/sagernet/sing v0.6.12-0.20250720033754-e79b303754a8/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
 github.com/sagernet/sing-mux v0.3.2 h1:meZVFiiStvHThb/trcpAkCrmtJOuItG5Dzl1RRP5/NE=
 github.com/sagernet/sing-mux v0.3.2/go.mod h1:pht8iFY4c9Xltj7rhVd208npkNaeCxzyXCgulDPLUDA=
 github.com/sagernet/sing-quic v0.5.0-beta.3 h1:X/acRNsqQNfDlmwE7SorHfaZiny5e67hqIzM/592ric=
diff --git a/protocol/tun/inbound.go b/protocol/tun/inbound.go
index e018b642..12a09871 100644
--- a/protocol/tun/inbound.go
+++ b/protocol/tun/inbound.go
@@ -135,8 +135,7 @@ func NewInbound(ctx context.Context, router adapter.Router, logger log.ContextLo
 	enableGSO := C.IsLinux && options.Stack == "gvisor" && platformInterface == nil && tunMTU > 0 && tunMTU < 49152
 	if tunMTU == 0 {
 		if platformInterface != nil && platformInterface.UnderNetworkExtension() {
-			// In Network Extension, when MTU exceeds 4064 (4096-UTUN_IF_HEADROOM_SIZE), the performance of tun will drop significantly, which may be a system bug.
-			tunMTU = 4064
+			tunMTU = 4000
 		} else {
 			tunMTU = 65535
 		}