diff --git a/ports/mimxrt/modmachine.c b/ports/mimxrt/modmachine.c
index 1212914d3b..4b6e8796f2 100644
--- a/ports/mimxrt/modmachine.c
+++ b/ports/mimxrt/modmachine.c
@@ -44,6 +44,8 @@
 
 #include CPU_HEADER_H
 
+#define MIMXRT_DEEPSLEEP_MIN (1)
+
 #if defined(MICROPY_HW_LED1_PIN)
 #define MICROPY_PY_MACHINE_LED_ENTRY { MP_ROM_QSTR(MP_QSTR_LED), MP_ROM_PTR(&machine_led_type) },
 #else
@@ -129,14 +131,15 @@ static void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
 NORETURN static void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_int_t seconds = mp_obj_get_int(args[0]) / 1000;
-        if (seconds > 0) {
-            machine_rtc_alarm_helper(seconds, false);
-            #ifdef MIMXRT117x_SERIES
-            GPC_CM_EnableIrqWakeup(GPC_CPU_MODE_CTRL_0, SNVS_HP_NON_TZ_IRQn, true);
-            #else
-            GPC_EnableIRQ(GPC, SNVS_HP_WRAPPER_IRQn);
-            #endif
+        if (seconds < MIMXRT_DEEPSLEEP_MIN) {
+            seconds = MIMXRT_DEEPSLEEP_MIN;
         }
+        machine_rtc_alarm_helper(seconds, false);
+        #ifdef MIMXRT117x_SERIES
+        GPC_CM_EnableIrqWakeup(GPC_CPU_MODE_CTRL_0, SNVS_HP_NON_TZ_IRQn, true);
+        #else
+        GPC_EnableIRQ(GPC, SNVS_HP_WRAPPER_IRQn);
+        #endif
     }
 
     #if defined(MIMXRT117x_SERIES)
diff --git a/ports/rp2/modmachine.c b/ports/rp2/modmachine.c
index 6189e7dc53..bc32ea6568 100644
--- a/ports/rp2/modmachine.c
+++ b/ports/rp2/modmachine.c
@@ -46,6 +46,7 @@
 
 #define RP2_RESET_PWRON (1)
 #define RP2_RESET_WDT (3)
+#define RP2_LIGHTSLEEP_MIN (1)
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
     { MP_ROM_QSTR(MP_QSTR_Pin),                 MP_ROM_PTR(&machine_pin_type) }, \
@@ -111,9 +112,9 @@ static void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
 
     if (n_args == 1) {
         delay_ms = mp_obj_get_int(args[0]);
-        if (delay_ms <= 1) {
-            // Sleep is too small, just use standard delay.
-            mp_hal_delay_ms(delay_ms);
+        if (delay_ms <= RP2_LIGHTSLEEP_MIN) {
+            // Sleep time is too small, just use standard delay.
+            mp_hal_delay_ms(RP2_LIGHTSLEEP_MIN);
             return;
         }
         use_timer_alarm = delay_ms < (1ULL << 32) / 1000;
diff --git a/ports/samd/modmachine.c b/ports/samd/modmachine.c
index 65dbf8a7f5..c0a05f4544 100644
--- a/ports/samd/modmachine.c
+++ b/ports/samd/modmachine.c
@@ -117,6 +117,9 @@ static void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     uint32_t freq = get_cpu_freq();
     if (n_args > 0) {
         duration = mp_obj_get_int(args[0]);
+        if (duration <= 0) {
+            return;
+        }
     }
     EIC_occured = false;
     // Slow down
@@ -130,7 +133,7 @@ static void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK3 | EIC_GCLK_ID;
     if (duration > 0) {
         uint32_t t0 = systick_ms;
-        while ((systick_ms - t0 < duration) && (EIC_occured == false)) {
+        while (((systick_ms - t0) < duration) && (EIC_occured == false)) {
             __WFI();
         }
     } else {