diff --git a/docs/networking.md b/docs/networking.md
index d9ec124d..08917348 100644
--- a/docs/networking.md
+++ b/docs/networking.md
@@ -62,6 +62,7 @@ Backends `fetch` and `wisp` support a couple of special settings in `config.net_
 | **dns_method** | str  | DNS method to use, either `static` or `doh`. `static`: use built-in DNS server, `doh`: use [DNS-over-HTTPS](https://en.wikipedia.org/wiki/DNS_over_HTTPS) (DoH). Defaults to `static` for `fetch` and to `doh` for `wisp` backend. |
 | **doh_server** | str  | Host name or IP address (and optional port number) of the DoH server if `dns_method` is `doh`. The value is expanded to the URL `https://DOH_SERVER/dns-query`. Default: `cloudflare-dns.com`. |
 | **cors_proxy** | str  | CORS proxy server URL, do not use a proxy if undefined. Default: undefined (`fetch` backend only). |
+| **mtu**        | int  | The MTU used for the virtual network. Increasing it can improve performance. This only works if the NIC type is `virtio`. Default: `1500` |
 
 #### Example `net_device` settings
 
diff --git a/src/browser/fake_network.js b/src/browser/fake_network.js
index e358f921..63923dec 100644
--- a/src/browser/fake_network.js
+++ b/src/browser/fake_network.js
@@ -45,18 +45,16 @@ const TCP_DYNAMIC_PORT_RANGE = TCP_DYNAMIC_PORT_END - TCP_DYNAMIC_PORT_START;
 
 const ETH_HEADER_SIZE     = 14;
 const ETH_PAYLOAD_OFFSET  = ETH_HEADER_SIZE;
-const ETH_PAYLOAD_SIZE    = 1500;
+const MTU_DEFAULT = 1500;
+//const ETH_PAYLOAD_SIZE    = 1500; //mtu
 const ETH_TRAILER_SIZE    = 4;
-const ETH_FRAME_SIZE      = ETH_HEADER_SIZE + ETH_PAYLOAD_SIZE + ETH_TRAILER_SIZE;
 const IPV4_HEADER_SIZE    = 20;
 const IPV4_PAYLOAD_OFFSET = ETH_PAYLOAD_OFFSET + IPV4_HEADER_SIZE;
-const IPV4_PAYLOAD_SIZE   = ETH_PAYLOAD_SIZE - IPV4_HEADER_SIZE;
+//const IPV4_PAYLOAD_SIZE   = ETH_PAYLOAD_SIZE - IPV4_HEADER_SIZE;
 const UDP_HEADER_SIZE     = 8;
 const UDP_PAYLOAD_OFFSET  = IPV4_PAYLOAD_OFFSET + UDP_HEADER_SIZE;
-const UDP_PAYLOAD_SIZE    = IPV4_PAYLOAD_SIZE - UDP_HEADER_SIZE;
 const TCP_HEADER_SIZE     = 20;
 const TCP_PAYLOAD_OFFSET  = IPV4_PAYLOAD_OFFSET + TCP_HEADER_SIZE;
-const TCP_PAYLOAD_SIZE    = IPV4_PAYLOAD_SIZE - TCP_HEADER_SIZE;
 const ICMP_HEADER_SIZE    = 4;
 
 const DEFAULT_DOH_SERVER = "cloudflare-dns.com";
@@ -161,15 +159,19 @@ class GrowableRingbuffer
     }
 }
 
-export function create_eth_encoder_buf()
+export function create_eth_encoder_buf(mtu = MTU_DEFAULT)
 {
+    const ETH_FRAME_SIZE = ETH_HEADER_SIZE + mtu + ETH_TRAILER_SIZE;
+    const IPV4_PAYLOAD_SIZE = mtu - IPV4_HEADER_SIZE;
+    const UDP_PAYLOAD_SIZE = IPV4_PAYLOAD_SIZE - UDP_HEADER_SIZE;
+
     const eth_frame = new Uint8Array(ETH_FRAME_SIZE);
     const buffer = eth_frame.buffer;
     const offset = eth_frame.byteOffset;
     return {
         eth_frame: eth_frame,
         eth_frame_view: new DataView(buffer),
-        eth_payload_view: new DataView(buffer, offset + ETH_PAYLOAD_OFFSET, ETH_PAYLOAD_SIZE),
+        eth_payload_view: new DataView(buffer, offset + ETH_PAYLOAD_OFFSET, mtu),
         ipv4_payload_view: new DataView(buffer, offset + IPV4_PAYLOAD_OFFSET, IPV4_PAYLOAD_SIZE),
         udp_payload_view: new DataView(buffer, offset + UDP_PAYLOAD_OFFSET, UDP_PAYLOAD_SIZE),
         text_encoder: new TextEncoder()
@@ -991,7 +993,7 @@ export function fake_tcp_connect(dport, adapter)
         throw new Error("pool of dynamic TCP port numbers exhausted, connection aborted");
     }
 
-    let conn = new TCPConnection();
+    let conn = new TCPConnection(adapter);
 
     conn.tuple = tuple;
     conn.hsrc = adapter.router_mac;
@@ -1000,7 +1002,6 @@ export function fake_tcp_connect(dport, adapter)
     conn.hdest = adapter.vm_mac;
     conn.dport = dport;
     conn.pdest = adapter.vm_ip;
-    conn.net = adapter;
     adapter.tcp_conn[tuple] = conn;
     conn.connect();
     return conn;
@@ -1017,10 +1018,13 @@ export function fake_tcp_probe(dport, adapter) {
 /**
  * @constructor
  */
-export function TCPConnection()
+export function TCPConnection(adapter)
 {
+    const IPV4_PAYLOAD_SIZE = (adapter.mtu || MTU_DEFAULT) - IPV4_HEADER_SIZE;
+    const TCP_PAYLOAD_SIZE = IPV4_PAYLOAD_SIZE - TCP_HEADER_SIZE;
+
     this.state = TCP_STATE_CLOSED;
-    this.net = null; // The adapter is stored here
+    this.net = adapter; // The adapter is stored here
     this.send_buffer = new GrowableRingbuffer(2048, 0);
     this.send_chunk_buf = new Uint8Array(TCP_PAYLOAD_SIZE);
     this.in_active_close = false;
diff --git a/src/browser/fetch_network.js b/src/browser/fetch_network.js
index 5d0195a9..74f763f6 100644
--- a/src/browser/fetch_network.js
+++ b/src/browser/fetch_network.js
@@ -33,7 +33,8 @@ export function FetchNetworkAdapter(bus, config)
     this.dns_method = config.dns_method || "static";
     this.doh_server = config.doh_server;
     this.tcp_conn = {};
-    this.eth_encoder_buf = create_eth_encoder_buf();
+    this.mtu = config.mtu;
+    this.eth_encoder_buf = create_eth_encoder_buf(this.mtu);
     this.fetch = (...args) => fetch(...args);
 
     // Ex: 'https://corsproxy.io/?'
@@ -55,9 +56,8 @@ FetchNetworkAdapter.prototype.destroy = function()
 FetchNetworkAdapter.prototype.on_tcp_connection = function(packet, tuple)
 {
     if(packet.tcp.dport === 80) {
-        let conn = new TCPConnection();
+        let conn = new TCPConnection(this);
         conn.state = TCP_STATE_SYN_RECEIVED;
-        conn.net = this;
         conn.on("data", on_data_http);
         conn.tuple = tuple;
         conn.accept(packet);
diff --git a/src/browser/main.js b/src/browser/main.js
index 4c2db9aa..cacc704f 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -2096,6 +2096,7 @@ function start_emulation(profile, query_args)
         settings.relay_url = query_args.get("relay_url");
         settings.disable_jit = bool_arg(query_args.get("disable_jit"));
         settings.disable_audio = bool_arg(query_args.get("mute"));
+        settings.mtu = parseInt(query_args.get("mtu"), 10) || undefined;
     }
 
     if(!settings.relay_url)
@@ -2255,7 +2256,8 @@ function start_emulation(profile, query_args)
         net_device: {
             type: settings.net_device_type || "ne2k",
             relay_url: settings.relay_url,
-            cors_proxy: settings.cors_proxy
+            cors_proxy: settings.cors_proxy,
+            mtu: settings.mtu
         },
         autostart: true,
 
diff --git a/src/browser/wisp_network.js b/src/browser/wisp_network.js
index e0de942f..c3063218 100644
--- a/src/browser/wisp_network.js
+++ b/src/browser/wisp_network.js
@@ -36,8 +36,9 @@ export function WispNetworkAdapter(wisp_url, bus, config)
     this.dns_method = config.dns_method || "doh";
     this.doh_server = config.doh_server;
     this.tcp_conn = {};
-    this.eth_encoder_buf = create_eth_encoder_buf();
-
+    this.mtu = config.mtu;
+    this.eth_encoder_buf = create_eth_encoder_buf(this.mtu);
+    
     this.bus.register("net" + this.id + "-mac", function(mac) {
         this.vm_mac = new Uint8Array(mac.split(":").map(function(x) { return parseInt(x, 16); }));
     }, this);
@@ -190,9 +191,8 @@ WispNetworkAdapter.prototype.destroy = function()
  */
 WispNetworkAdapter.prototype.on_tcp_connection = function(packet, tuple)
 {
-    let conn = new TCPConnection();
+    let conn = new TCPConnection(this);
     conn.state = TCP_STATE_SYN_RECEIVED;
-    conn.net = this;
     conn.tuple = tuple;
     conn.stream_id = this.last_stream++;
     this.tcp_conn[tuple] = conn;
diff --git a/src/cpu.js b/src/cpu.js
index 67659731..186e571a 100644
--- a/src/cpu.js
+++ b/src/cpu.js
@@ -1210,7 +1210,7 @@ CPU.prototype.init = function(settings, device_bus)
         }
         else if(settings.net_device.type === "virtio")
         {
-            this.devices.virtio_net = new VirtioNet(this, device_bus, settings.preserve_mac_from_state_image);
+            this.devices.virtio_net = new VirtioNet(this, device_bus, settings.preserve_mac_from_state_image, settings.net_device.mtu);
         }
 
         if(settings.fs9p)
diff --git a/src/virtio_net.js b/src/virtio_net.js
index ea6e08bd..ee7ad94c 100644
--- a/src/virtio_net.js
+++ b/src/virtio_net.js
@@ -24,8 +24,9 @@ const VIRTIO_NET_CTRL_MAC_ADDR_SET = 1;
  * @param {CPU} cpu
  * @param {BusConnector} bus
  * @param {Boolean} preserve_mac_from_state_image
+ * @param {Number} mtu
  */
-export function VirtioNet(cpu, bus, preserve_mac_from_state_image)
+export function VirtioNet(cpu, bus, preserve_mac_from_state_image, mtu = 1500)
 {
     /** @const @type {BusConnector} */
     this.bus = bus;
@@ -177,7 +178,7 @@ export function VirtioNet(cpu, bus, preserve_mac_from_state_image)
                 {
                     bytes: 2,
                     name: "mtu",
-                    read: () => 1500,
+                    read: () => mtu,
                     write: data => {},
                 }
            ])
diff --git a/v86.d.ts b/v86.d.ts
index 13c6ecbb..29f762ab 100644
--- a/v86.d.ts
+++ b/v86.d.ts
@@ -333,6 +333,7 @@ export interface V86Options {
         dns_method?: "static" | "doh";
         doh_server?: string;
         cors_proxy?: string;
+        mtu?: number;
     };
 }