diff --git a/CMakeLists.txt b/CMakeLists.txt
index eda4f18..2ef6192 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@ target_include_directories(uart_bridge PUBLIC
 target_link_libraries(uart_bridge
 	pico_multicore
 	pico_stdlib
+	hardware_flash
 	tinyusb_device)
 
 pico_add_extra_outputs(uart_bridge)
diff --git a/serial.h b/serial.h
new file mode 100644
index 0000000..4525667
--- /dev/null
+++ b/serial.h
@@ -0,0 +1,3 @@
+#pragma once
+
+extern char serial[17];
diff --git a/uart-bridge.c b/uart-bridge.c
index aebbdf6..27749e9 100644
--- a/uart-bridge.c
+++ b/uart-bridge.c
@@ -10,6 +10,9 @@
 #include <pico/stdlib.h>
 #include <string.h>
 #include <tusb.h>
+#include <hardware/flash.h>
+
+#include "serial.h"
 
 #if !defined(MIN)
 #define MIN(a, b) ((a > b) ? b : a)
@@ -263,12 +266,23 @@ void init_uart_data(uint8_t itf) {
 			parity_usb2uart(ud->usb_lc.parity));
 }
 
+static inline void init_serial() {
+	uint8_t id[8];
+	flash_get_unique_id(id);
+	for (int i = 0; i < 8; ++i) {
+		sprintf(serial + 2 * i, "%X", id[i]);
+	}
+	serial[16] = '\0';
+}
+
 int main(void)
 {
 	int itf;
 
 	set_sys_clock_khz(250000, false);
 
+	init_serial();
+
 	for (itf = 0; itf < CFG_TUD_CDC; itf++)
 		init_uart_data(itf);
 
diff --git a/usb-descriptors.c b/usb-descriptors.c
index 5c10798..4405f36 100644
--- a/usb-descriptors.c
+++ b/usb-descriptors.c
@@ -11,6 +11,8 @@
 
 #include <tusb.h>
 
+#include "serial.h"
+
 #define DESC_STR_MAX 20
 
 #define USBD_VID 0x2E8A /* Raspberry Pi */
@@ -68,10 +70,12 @@ static const uint8_t usbd_desc_cfg[USBD_DESC_LEN] = {
 		USBD_CDC_IN_OUT_MAX_SIZE),
 };
 
-static const char *const usbd_desc_str[] = {
+char serial[17];
+
+static char *const usbd_desc_str[] = {
 	[USBD_STR_MANUF] = "Raspberry Pi",
 	[USBD_STR_PRODUCT] = "Pico",
-	[USBD_STR_SERIAL] = "000000000000",
+	[USBD_STR_SERIAL] = serial,
 	[USBD_STR_CDC] = "Board CDC",
 };