diff --git a/ports/esp32/main.c b/ports/esp32/main.c
index 5b1be4cf74..eebf183cd6 100644
--- a/ports/esp32/main.c
+++ b/ports/esp32/main.c
@@ -53,11 +53,9 @@
 #define MP_TASK_PRIORITY        (ESP_TASK_PRIO_MIN + 1)
 #define MP_TASK_STACK_SIZE      (16 * 1024)
 #define MP_TASK_STACK_LEN       (MP_TASK_STACK_SIZE / sizeof(StackType_t))
-#define MP_TASK_HEAP_SIZE       (92 * 1024)
 
 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];
 
 void mp_task(void *pvParameter) {
     volatile uint32_t sp = (uint32_t)get_sp();
@@ -66,11 +64,15 @@ void mp_task(void *pvParameter) {
     #endif
     uart_init();
 
+    // Allocate the uPy heap using malloc and get the largest available region
+    size_t mp_task_heap_size = heap_caps_get_largest_free_block(MALLOC_CAP_8BIT);
+    void *mp_task_heap = malloc(mp_task_heap_size);
+
 soft_reset:
     // initialise the stack pointer for the main thread
     mp_stack_set_top((void *)sp);
     mp_stack_set_limit(MP_TASK_STACK_SIZE - 1024);
-    gc_init(mp_task_heap, mp_task_heap + sizeof(mp_task_heap));
+    gc_init(mp_task_heap, mp_task_heap + mp_task_heap_size);
     mp_init();
     mp_obj_list_init(mp_sys_path, 0);
     mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR_));