diff --git a/src/codal_port/drv_softtimer.c b/src/codal_port/drv_softtimer.c
index b244008..e58ee26 100644
--- a/src/codal_port/drv_softtimer.c
+++ b/src/codal_port/drv_softtimer.c
@@ -43,16 +43,18 @@ void microbit_soft_timer_deinit(void) {
     microbit_soft_timer_paused = false;
 }
 
-void microbit_soft_timer_handler_run(void) {
+static void microbit_soft_timer_handler_run(bool run_callbacks) {
     uint32_t ticks_ms = mp_hal_ticks_ms();
     microbit_soft_timer_entry_t *heap = MP_STATE_PORT(soft_timer_heap);
     while (heap != NULL && TICKS_DIFF(heap->expiry_ms, ticks_ms) <= 0) {
         microbit_soft_timer_entry_t *entry = heap;
         heap = (microbit_soft_timer_entry_t *)mp_pairheap_pop(microbit_soft_timer_lt, &heap->pairheap);
-        if (entry->flags & MICROBIT_SOFT_TIMER_FLAG_PY_CALLBACK) {
-            mp_sched_schedule(entry->py_callback, MP_OBJ_FROM_PTR(entry));
-        } else {
-            entry->c_callback(entry);
+        if (run_callbacks) {
+            if (entry->flags & MICROBIT_SOFT_TIMER_FLAG_PY_CALLBACK) {
+                mp_sched_schedule(entry->py_callback, MP_OBJ_FROM_PTR(entry));
+            } else {
+                entry->c_callback(entry);
+            }
         }
         if (entry->mode == MICROBIT_SOFT_TIMER_MODE_PERIODIC) {
             entry->expiry_ms += entry->delta_ms;
@@ -65,7 +67,7 @@ void microbit_soft_timer_handler_run(void) {
 // This function can be executed at interrupt priority.
 void microbit_soft_timer_handler(void) {
     if (!microbit_soft_timer_paused) {
-        microbit_soft_timer_handler_run();
+        microbit_soft_timer_handler_run(true);
     }
 }
 
@@ -77,10 +79,10 @@ void microbit_soft_timer_insert(microbit_soft_timer_entry_t *entry, uint32_t ini
     MICROPY_END_ATOMIC_SECTION(atomic_state);
 }
 
-void microbit_soft_timer_set_pause(bool paused) {
+void microbit_soft_timer_set_pause(bool paused, bool run_callbacks) {
     if (microbit_soft_timer_paused && !paused) {
         // Explicitly run the soft timer before unpausing, to catch up on any queued events.
-        microbit_soft_timer_handler_run();
+        microbit_soft_timer_handler_run(run_callbacks);
     }
     microbit_soft_timer_paused = paused;
 }
diff --git a/src/codal_port/drv_softtimer.h b/src/codal_port/drv_softtimer.h
index f178f78..c59d6ea 100644
--- a/src/codal_port/drv_softtimer.h
+++ b/src/codal_port/drv_softtimer.h
@@ -51,7 +51,7 @@ extern bool microbit_outer_nlr_will_handle_soft_timer_exceptions;
 void microbit_soft_timer_deinit(void);
 void microbit_soft_timer_handler(void);
 void microbit_soft_timer_insert(microbit_soft_timer_entry_t *entry, uint32_t initial_delta_ms);
-void microbit_soft_timer_set_pause(bool paused);
+void microbit_soft_timer_set_pause(bool paused, bool run_callbacks);
 uint32_t microbit_soft_timer_get_ms_to_next_expiry(void);
 
 #endif // MICROPY_INCLUDED_CODAL_PORT_DRV_SOFTTIMER_H
diff --git a/src/codal_port/modpower.c b/src/codal_port/modpower.c
index 5ca9add..a707e4a 100644
--- a/src/codal_port/modpower.c
+++ b/src/codal_port/modpower.c
@@ -93,9 +93,11 @@ STATIC mp_obj_t power_deep_sleep(size_t n_args, const mp_obj_t *pos_args, mp_map
         bool wake = wake_on_ms;
         uint32_t ms = remain_ms;
 
+        // Pause the soft timer.
+        microbit_soft_timer_set_pause(true, true);
+
         // If run_every is true then check if any soft timers will expire and need to wake the device.
         if (args[ARG_run_every].u_bool) {
-            microbit_soft_timer_set_pause(true);
             uint32_t soft_timer_ms = microbit_soft_timer_get_ms_to_next_expiry();
             if (soft_timer_ms != UINT32_MAX) {
                 // A soft timer will expire in "ms" milliseconds.
@@ -109,8 +111,8 @@ STATIC mp_obj_t power_deep_sleep(size_t n_args, const mp_obj_t *pos_args, mp_map
         // Enter low power state.
         bool interrupted = microbit_hal_power_deep_sleep(wake, ms);
 
-        // Resume soft timer (doesn't hurt to resume even if it wasn't paused).
-        microbit_soft_timer_set_pause(false);
+        // Resume the soft timer, and run outstanding events if run_every=True.
+        microbit_soft_timer_set_pause(false, args[ARG_run_every].u_bool);
 
         // Run all outstanding scheduled functions.
         while (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) {