diff --git a/lib/utils/pyexec.c b/lib/utils/pyexec.c
index 0522de7973..5d72419d1a 100644
--- a/lib/utils/pyexec.c
+++ b/lib/utils/pyexec.c
@@ -114,11 +114,11 @@ STATIC int parse_compile_execute(const void *source, mp_parse_input_kind_t input
             mp_hal_stdout_tx_strn("\x04", 1);
         }
         // check for SystemExit
-        if (mp_obj_is_subclass_fast(mp_obj_get_type((mp_obj_t)nlr.ret_val), &mp_type_SystemExit)) {
+        if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(((mp_obj_base_t*)nlr.ret_val)->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
             // at the moment, the value of SystemExit is unused
             ret = pyexec_system_exit;
         } else {
-            mp_obj_print_exception(&mp_plat_print, (mp_obj_t)nlr.ret_val);
+            mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
             ret = 0;
         }
     }
@@ -131,8 +131,8 @@ STATIC int parse_compile_execute(const void *source, mp_parse_input_kind_t input
         {
             size_t n_pool, n_qstr, n_str_data_bytes, n_total_bytes;
             qstr_pool_info(&n_pool, &n_qstr, &n_str_data_bytes, &n_total_bytes);
-            printf("qstr:\n  n_pool=" UINT_FMT "\n  n_qstr=" UINT_FMT "\n  "
-                   "n_str_data_bytes=" UINT_FMT "\n  n_total_bytes=" UINT_FMT "\n",
+            printf("qstr:\n  n_pool=%u\n  n_qstr=%u\n  "
+                   "n_str_data_bytes=%u\n  n_total_bytes=%u\n",
                    (unsigned)n_pool, (unsigned)n_qstr, (unsigned)n_str_data_bytes, (unsigned)n_total_bytes);
         }
 
diff --git a/lib/utils/sys_stdio_mphal.c b/lib/utils/sys_stdio_mphal.c
index fc8a74e7d6..234db0829b 100644
--- a/lib/utils/sys_stdio_mphal.c
+++ b/lib/utils/sys_stdio_mphal.c
@@ -53,12 +53,12 @@ STATIC const sys_stdio_obj_t stdio_buffer_obj;
 #endif
 
 void stdio_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
-    sys_stdio_obj_t *self = self_in;
+    sys_stdio_obj_t *self = MP_OBJ_TO_PTR(self_in);
     mp_printf(print, "<io.FileIO %d>", self->fd);
 }
 
 STATIC mp_uint_t stdio_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode) {
-    sys_stdio_obj_t *self = self_in;
+    sys_stdio_obj_t *self = MP_OBJ_TO_PTR(self_in);
     if (self->fd == STDIO_FD_IN) {
         for (uint i = 0; i < size; i++) {
             int c = mp_hal_stdin_rx_chr();
@@ -75,7 +75,7 @@ STATIC mp_uint_t stdio_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *er
 }
 
 STATIC mp_uint_t stdio_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
-    sys_stdio_obj_t *self = self_in;
+    sys_stdio_obj_t *self = MP_OBJ_TO_PTR(self_in);
     if (self->fd == STDIO_FD_OUT || self->fd == STDIO_FD_ERR) {
         mp_hal_stdout_tx_strn_cooked(buf, size);
         return size;
@@ -156,7 +156,7 @@ STATIC const mp_obj_type_t stdio_buffer_obj_type = {
     .getiter = mp_identity_getiter,
     .iternext = mp_stream_unbuffered_iter,
     .protocol = &stdio_buffer_obj_stream_p,
-    .locals_dict = (mp_obj_t)&stdio_locals_dict,
+    .locals_dict = (mp_obj_dict_t*)&stdio_locals_dict,
 };
 
 STATIC const sys_stdio_obj_t stdio_buffer_obj = {{&stdio_buffer_obj_type}, .fd = 0}; // fd unused