diff --git a/shared/runtime/softtimer.c b/shared/runtime/softtimer.c
index 92a0d6d511..b154cd9d7b 100644
--- a/shared/runtime/softtimer.c
+++ b/shared/runtime/softtimer.c
@@ -28,6 +28,7 @@
 #include "py/gc.h"
 #include "py/mphal.h"
 #include "py/runtime.h"
+#include "shared/runtime/mpirq.h"
 #include "softtimer.h"
 
 #ifdef MICROPY_SOFT_TIMER_TICKS_MS
@@ -88,7 +89,11 @@ void soft_timer_handler(void) {
         soft_timer_entry_t *entry = heap;
         heap = (soft_timer_entry_t *)mp_pairheap_pop(soft_timer_lt, &heap->pairheap);
         if (entry->flags & SOFT_TIMER_FLAG_PY_CALLBACK) {
-            mp_sched_schedule(entry->py_callback, MP_OBJ_FROM_PTR(entry));
+            if (mp_irq_dispatch(entry->py_callback, MP_OBJ_FROM_PTR(entry),
+                entry->flags & SOFT_TIMER_FLAG_HARD_CALLBACK)) {
+                // Uncaught exception; disable the callback so it doesn't run again.
+                entry->mode = SOFT_TIMER_MODE_ONE_SHOT;
+            }
         } else if (entry->c_callback) {
             entry->c_callback(entry);
         }
diff --git a/shared/runtime/softtimer.h b/shared/runtime/softtimer.h
index 6921c9f47d..464d2067ed 100644
--- a/shared/runtime/softtimer.h
+++ b/shared/runtime/softtimer.h
@@ -30,6 +30,7 @@
 
 #define SOFT_TIMER_FLAG_PY_CALLBACK (1)
 #define SOFT_TIMER_FLAG_GC_ALLOCATED (2)
+#define SOFT_TIMER_FLAG_HARD_CALLBACK (4)
 
 #define SOFT_TIMER_MODE_ONE_SHOT (1)
 #define SOFT_TIMER_MODE_PERIODIC (2)