diff --git a/esp32/main.c b/esp32/main.c
index 091cbddc9..e21bb4bb9 100644
--- a/esp32/main.c
+++ b/esp32/main.c
@@ -59,12 +59,15 @@ STATIC StaticTask_t mp_task_tcb;
 STATIC StackType_t mp_task_stack[MP_TASK_STACK_LEN] __attribute__((aligned (8)));
 STATIC uint8_t mp_task_heap[MP_TASK_HEAP_SIZE];
 
+extern uint32_t reset_cause;
+
 void mp_task(void *pvParameter) {
     volatile uint32_t sp = (uint32_t)get_sp();
     #if MICROPY_PY_THREAD
     mp_thread_init(&mp_task_stack[0], MP_TASK_STACK_LEN);
     #endif
     uart_init();
+    machine_init();
 
 soft_reset:
     // initialise the stack pointer for the main thread
@@ -111,6 +114,7 @@ void mp_task(void *pvParameter) {
 
     mp_deinit();
     fflush(stdout);
+    reset_cause = MACHINE_SOFT_RESET;
     goto soft_reset;
 }
 
diff --git a/esp32/modmachine.c b/esp32/modmachine.c
index 58bffc4de..b97b1501b 100644
--- a/esp32/modmachine.c
+++ b/esp32/modmachine.c
@@ -34,6 +34,7 @@
 #include "freertos/task.h"
 #include "rom/ets_sys.h"
 #include "esp_system.h"
+#include "rom/rtc.h"
 
 #include "py/obj.h"
 #include "py/runtime.h"
@@ -45,6 +46,12 @@
 
 #if MICROPY_PY_MACHINE
 
+uint32_t reset_cause;
+
+void machine_init() {
+    reset_cause = rtc_get_reset_reason(0);
+}
+
 STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
     if (n_args == 0) {
         // get
@@ -70,6 +77,11 @@ STATIC mp_obj_t machine_reset(void) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
+STATIC mp_obj_t machine_reset_cause(void) {
+    return mp_obj_new_int(reset_cause);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
+
 STATIC mp_obj_t machine_unique_id(void) {
     uint8_t chipid[6];
     esp_efuse_mac_get_default(chipid);
@@ -105,6 +117,7 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
 
     { 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_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) },
     { MP_ROM_QSTR(MP_QSTR_unique_id), MP_ROM_PTR(&machine_unique_id_obj) },
     { MP_ROM_QSTR(MP_QSTR_idle), MP_ROM_PTR(&machine_idle_obj) },
 
@@ -121,6 +134,21 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_PWM), MP_ROM_PTR(&machine_pwm_type) },
     { MP_ROM_QSTR(MP_QSTR_SPI), MP_ROM_PTR(&mp_machine_soft_spi_type) },
     { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&machine_uart_type) },
+
+    // These are conflated, unfortunately
+    // https://github.com/espressif/esp-idf/issues/494#issuecomment-291921540
+    //
+    // Per @igrr:
+    // "ESP32 doesn't have a dedicated reset line, instead CHIP_PU pin is 
+    //  used both as a power down pin and a reset pin. So a low pulse on 
+    //  CHIP_PU is equivalent to a power off followed by power on. 
+    //  This is why an external reset is logged as a power on reset."
+    
+    { MP_ROM_QSTR(MP_QSTR_PWRON_RESET),  MP_OBJ_NEW_SMALL_INT(POWERON_RESET) },
+    { MP_ROM_QSTR(MP_QSTR_HARD_RESET),  MP_OBJ_NEW_SMALL_INT(POWERON_RESET) },
+    { MP_ROM_QSTR(MP_QSTR_WDT_RESET),  MP_OBJ_NEW_SMALL_INT(RTCWDT_CPU_RESET) },
+    { MP_ROM_QSTR(MP_QSTR_DEEPSLEEP_RESET),  MP_OBJ_NEW_SMALL_INT(RTCWDT_RTC_RESET) },
+    { MP_ROM_QSTR(MP_QSTR_SOFT_RESET),  MP_OBJ_NEW_SMALL_INT(MACHINE_SOFT_RESET) },
 };
 
 STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);
diff --git a/esp32/modmachine.h b/esp32/modmachine.h
index 3dace35d4..1123ec4e9 100644
--- a/esp32/modmachine.h
+++ b/esp32/modmachine.h
@@ -3,6 +3,10 @@
 
 #include "py/obj.h"
 
+#define MACHINE_SOFT_RESET 0
+
+void machine_init();
+
 extern const mp_obj_type_t machine_pin_type;
 extern const mp_obj_type_t machine_touchpad_type;
 extern const mp_obj_type_t machine_adc_type;