diff --git a/firmwares/atmegaxxu2/arduino-usbserial/Descriptors.c b/firmwares/atmegaxxu2/arduino-usbserial/Descriptors.c
index 705dddf..0557403 100755
--- a/firmwares/atmegaxxu2/arduino-usbserial/Descriptors.c
+++ b/firmwares/atmegaxxu2/arduino-usbserial/Descriptors.c
@@ -54,7 +54,7 @@
  *  number of device configurations. The descriptor is read out by the USB host when the enumeration
  *  process begins.
  */
-USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
+const USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
 {
 	.Header                 = {.Size = sizeof(USB_Descriptor_Device_t), .Type = DTYPE_Device},
 		
@@ -82,7 +82,7 @@ USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
  *  and endpoints. The descriptor is read out by the USB host during the enumeration process when selecting
  *  a configuration so that the host may correctly communicate with the USB device.
  */
-USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
+const USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
 {
 	.Config = 
 		{
@@ -190,7 +190,7 @@ USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
  *  the string descriptor with index 0 (the first index). It is actually an array of 16-bit integers, which indicate
  *  via the language ID table available at USB.org what languages the device supports for its string descriptors.
  */
-USB_Descriptor_String_t PROGMEM LanguageString =
+const USB_Descriptor_String_t PROGMEM LanguageString =
 {
 	.Header                 = {.Size = USB_STRING_LEN(1), .Type = DTYPE_String},
 		
@@ -201,7 +201,7 @@ USB_Descriptor_String_t PROGMEM LanguageString =
  *  form, and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
  *  Descriptor.
  */
-USB_Descriptor_String_t PROGMEM ManufacturerString =
+const USB_Descriptor_String_t PROGMEM ManufacturerString =
 {
 	.Header                 = {.Size = USB_STRING_LEN(24), .Type = DTYPE_String},
 		
@@ -212,7 +212,7 @@ USB_Descriptor_String_t PROGMEM ManufacturerString =
  *  and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
  *  Descriptor.
  */
-USB_Descriptor_String_t PROGMEM ProductString =
+const USB_Descriptor_String_t PROGMEM ProductString =
 {
 	#if (ARDUINO_MODEL_PID == ARDUINO_UNO_PID)
 		.Header                 = {.Size = USB_STRING_LEN(11), .Type = DTYPE_String},