diff --git a/esp8266/modmachine.c b/esp8266/modmachine.c
index 89cf4fb..0dab510 100644
--- a/esp8266/modmachine.c
+++ b/esp8266/modmachine.c
@@ -63,6 +63,12 @@
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
+STATIC mp_obj_t machine_unique_id(void) {
+    uint32_t id = system_get_chip_id();
+    return mp_obj_new_bytes((byte*)&id, sizeof(id));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
+
 typedef struct _esp_timer_obj_t {
     mp_obj_base_t base;
     os_timer_t timer;
@@ -146,6 +152,7 @@
 
     { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&machine_freq_obj) },
     { MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&machine_reset_obj) },
+    { MP_ROM_QSTR(MP_QSTR_unique_id), MP_ROM_PTR(&machine_unique_id_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_Timer), MP_ROM_PTR(&esp_timer_type) },
     { MP_ROM_QSTR(MP_QSTR_Pin), MP_ROM_PTR(&pyb_pin_type) },