diff --git a/extmod/moductypes.c b/extmod/moductypes.c
index 9995f637b8..6249a49406 100644
--- a/extmod/moductypes.c
+++ b/extmod/moductypes.c
@@ -125,7 +125,7 @@ STATIC mp_obj_t uctypes_struct_make_new(const mp_obj_type_t *type, size_t n_args
     mp_arg_check_num(n_args, n_kw, 2, 3, false);
     mp_obj_uctypes_struct_t *o = m_new_obj(mp_obj_uctypes_struct_t);
     o->base.type = type;
-    o->addr = (void*)(uintptr_t)mp_obj_get_int(args[0]);
+    o->addr = (void*)(uintptr_t)mp_obj_int_get_truncated(args[0]);
     o->desc = args[1];
     o->flags = LAYOUT_NATIVE;
     if (n_args == 3) {