diff --git a/web/assets/js/model/inbound.js b/web/assets/js/model/inbound.js
index ba2304ef..8d4b6819 100644
--- a/web/assets/js/model/inbound.js
+++ b/web/assets/js/model/inbound.js
@@ -317,7 +317,7 @@ TcpStreamSettings.TcpResponse = class extends XrayCommonClass {
 
 class KcpStreamSettings extends XrayCommonClass {
     constructor(
-        mtu = 1350,
+        mtu = 1250,
         tti = 50,
         uplinkCapacity = 5,
         downlinkCapacity = 20,
@@ -2506,7 +2506,7 @@ Inbound.HttpSettings.HttpAccount = class extends XrayCommonClass {
 Inbound.WireguardSettings = class extends XrayCommonClass {
     constructor(
         protocol,
-        mtu = 1420,
+        mtu = 1250,
         secretKey = Wireguard.generateKeypair().privateKey,
         peers = [new Inbound.WireguardSettings.Peer()],
         noKernelTun = false
diff --git a/web/assets/js/model/outbound.js b/web/assets/js/model/outbound.js
index 295ac812..6fe34982 100644
--- a/web/assets/js/model/outbound.js
+++ b/web/assets/js/model/outbound.js
@@ -164,7 +164,7 @@ class TcpStreamSettings extends CommonClass {
 
 class KcpStreamSettings extends CommonClass {
     constructor(
-        mtu = 1350,
+        mtu = 1250,
         tti = 50,
         uplinkCapacity = 5,
         downlinkCapacity = 20,
@@ -1233,7 +1233,7 @@ Outbound.HttpSettings = class extends CommonClass {
 
 Outbound.WireguardSettings = class extends CommonClass {
     constructor(
-        mtu = 1420,
+        mtu = 1250,
         secretKey = '',
         address = [''],
         workers = 2,