diff --git a/common/modules/mixly-modules/web/burn-upload.js b/common/modules/mixly-modules/web/burn-upload.js
index 8c8c06db..74dc0d36 100644
--- a/common/modules/mixly-modules/web/burn-upload.js
+++ b/common/modules/mixly-modules/web/burn-upload.js
@@ -670,9 +670,9 @@ BU.uploadWithAmpy = (portName) => {
     const editor = mainWorkspace.getEditorsManager().getActive();
     const port = Serial.getPort(portName);
     let useBuffer = true, dataLength = 256;
-    if (port instanceof window.USBDevice) {
+    if (port.constructor.name === 'USBDevice') {
         dataLength = 64;
-    } else if (port instanceof window.HIDDevice) {
+    } else if (port.constructor.name === 'HIDDevice') {
         dataLength = 31;
     }
     const layerNum = layer.open({
diff --git a/common/modules/mixly-modules/web/serial.js b/common/modules/mixly-modules/web/serial.js
index b17035ee..4e3f0ac6 100644
--- a/common/modules/mixly-modules/web/serial.js
+++ b/common/modules/mixly-modules/web/serial.js
@@ -113,11 +113,11 @@ class WebSerial extends Serial {
         }
 
         this.getHandler = function (device) {
-            if (device instanceof window.SerialPort) {
+            if (device.constructor.name === 'SerialPort') {
                 return SerialPort;
-            } else if (device instanceof window.HIDDevice) {
+            } else if (device.constructor.name === 'HIDDevice') {
                 return HID;
-            } else if (device instanceof window.USBDevice) {
+            } else if (device.constructor.name === 'USBDevice') {
                 if (this.devicesRegistry.hasKey('usbmini')) {
                     return USBMini;
                 } else {