diff --git a/lib/usb_dfu.c b/lib/usb_dfu.c
index 878c3a4..c8ea755 100644
--- a/lib/usb_dfu.c
+++ b/lib/usb_dfu.c
@@ -13,9 +13,9 @@
  *
  */
 /** library for USB DFU to write on internal flash (code)
- *  @file usb_dfu.c
+ *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @date 2017
+ *  @date 2017-2019
  */
 
 /* standard libraries */
@@ -60,7 +60,7 @@ static const struct usb_device_descriptor usb_dfu_device = {
 	.bcdDevice = 0x0000, /**< Device Release Number: board version number */
 	.iManufacturer = 1, /**< the index of the string in the string table that represents the name of the manufacturer of this device */
 	.iProduct = 2, /**< the index of the string in the string table that represents the name of the product */
-	.iSerialNumber = 0, /**< the index of the string in the string table that represents the serial number of this item in string form */
+	.iSerialNumber = 3, /**< the index of the string in the string table that represents the serial number of this item in string form */
 	.bNumConfigurations = 1, /**< the number of possible configurations this device has */
 };
 
@@ -88,7 +88,7 @@ static const struct usb_interface_descriptor usb_dfu_interface = {
 	.bInterfaceClass = 0xFE, /**< DFU interface class (not defined in libopencm3 dfu lib) */
 	.bInterfaceSubClass = 1, /**< DFU interface subclass (not defined in libopencm3 dfu lib) */
 	.bInterfaceProtocol = 2,  /**< DFU interface mode protocol (not defined in libopencm3 dfu lib) */
-	.iInterface = 3, /**< the index of the string in the string table that represents interface description */
+	.iInterface = 4, /**< the index of the string in the string table that represents interface description */
 	.extra = &usb_dfu_functional, /**< point to functional descriptor */
 	.extralen = sizeof(usb_dfu_functional), /**< size of functional descriptor */
 };
@@ -115,12 +115,16 @@ static const struct usb_config_descriptor usb_dfu_configuration = {
 	.interface = usb_dfu_interfaces, /**< pointer to an array of interfaces */
 };
 
+/** device ID used as serial number */
+static char usb_serial[] = "00112233445566778899aabb";
+
 /** USB string table
  *  @note starts with index 1
  */
 static const char *usb_dfu_strings[] = {
 	"CuVoodoo", /**< manufacturer string */
 	"CuVoodoo STM32F1xx DFU bootloader", /**< product string */
+	(const char*)usb_serial, /**< device ID used as serial number */
 	"DFU bootloader (DFU mode)", /**< DFU interface string */
 };
 
@@ -284,6 +288,27 @@ static enum usbd_request_return_codes usb_dfu_control_request(usbd_device *usbd_
 
 void usb_dfu_setup(void)
 {
+	// set serial
+	for (uint8_t i = 0; i < LENGTH(usb_serial) - 1; i++) { // write the serial
+		uint32_t id; // current ID part
+		if (i < 8) {
+			id = DESIG_UNIQUE_ID0;
+		} else if (i < 16) {
+			id = DESIG_UNIQUE_ID1;
+		} else {
+			id = DESIG_UNIQUE_ID2;
+		}
+		// transform into character
+		char c = (id >> ((7 - (i % 8)) * 4)) & 0x0f; // get nibble
+		if (c < 10) {
+			c = '0' + c;
+		} else {
+			c = 'a' + (c - 10);
+		}
+		// set character
+		usb_serial[i] = c;
+	}
+
 	rcc_periph_reset_pulse(RST_USB); // reset USB peripheral
 	usb_disconnect(); // disconnect to force re-enumeration
 	rcc_periph_clock_enable(RCC_GPIOA); // enable clock for GPIO used for USB
diff --git a/lib/usb_dfu.h b/lib/usb_dfu.h
index 30ca731..ab7f487 100644
--- a/lib/usb_dfu.h
+++ b/lib/usb_dfu.h
@@ -13,9 +13,9 @@
  *
  */
 /** library for USB DFU to write on internal flash (API)
- *  @file usb_dfu.h
+ *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @date 2017
+ *  @date 2017-2019
  */
 #pragma once