diff --git a/Assets/dll/melonDS.wbx.zst b/Assets/dll/melonDS.wbx.zst
old mode 100644
new mode 100755
index e3181ce8342..8de47ce4497
Binary files a/Assets/dll/melonDS.wbx.zst and b/Assets/dll/melonDS.wbx.zst differ
diff --git a/waterbox/melon/BizConsoleCreator.cpp b/waterbox/melon/BizConsoleCreator.cpp
index 53983eef177..ff5fe93a860 100644
--- a/waterbox/melon/BizConsoleCreator.cpp
+++ b/waterbox/melon/BizConsoleCreator.cpp
@@ -63,6 +63,17 @@ static std::unique_ptr<T> CreateBiosImage(u8* biosData, u32 biosLength, std::opt
 	return std::move(bios);
 }
 
+static bool isValidMacAddress(const melonDS::MacAddress& mac)
+{
+    // Invalid 48bit MAC address: FF:FF:FF:FF:FF:FF
+    const bool isAll0xFF = mac[0] == 0xFF && mac[1] == 0xFF && mac[2] == 0xFF && mac[3] == 0xFF && mac[4] == 0xFF && mac[5] == 0xFF;
+
+    // Broadcast channel 48bit MAC address: 03:09:BF:XX:XX:XX
+    const bool isBroadsast = mac[0] == 0x03 && mac[1] == 0x09 && mac[2] == 0xBF;
+
+    return !isAll0xFF || !isBroadsast;
+}
+
 static void SanitizeExternalFirmware(melonDS::Firmware& firmware)
 {
 	auto& header = firmware.GetHeader();
@@ -84,7 +95,17 @@ static void SanitizeExternalFirmware(melonDS::Firmware& firmware)
 		memset(&header.Bytes[0x28], 0xFF, 2);
 	}
 
-	memcpy(&header.Bytes[0x2C], &defaultHeader.Bytes[0x2C], 0x136);
+	memcpy(&header.Bytes[0x2C], &defaultHeader.Bytes[0x2C], 10);
+
+	// MAC address offset is 0x36, so we skip writing from 0x36 to 0x3B (48 bit)
+	// to avoid copying melonDS default MAC address 0x0009BF112233
+	// only if the external firmware MAC address is valid
+	if (!isValidMacAddress(header.MacAddr))
+	{
+		memcpy(&header.Bytes[0x36], &defaultHeader.Bytes[0x36], 6);
+	}
+
+	memcpy(&header.Bytes[0x3C], &defaultHeader.Bytes[0x3C], 0x126);
 	memset(&header.Bytes[0x162], 0xFF, 0x9E);
 
 	if (isDSiFw)