1 files changed, 2 insertions, 0 deletions
diff --git a/py/obj.h b/py/obj.h
index b34581c8b..e29f3efea 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -246,6 +246,7 @@ typedef struct _mp_stream_p_t {
     machine_int_t (*read)(mp_obj_t obj, void *buf, machine_uint_t size, int *errcode);
     machine_int_t (*write)(mp_obj_t obj, const void *buf, machine_uint_t size, int *errcode);
     // add seek() ?
+    int is_bytes : 1;
 } mp_stream_p_t;
 
 struct _mp_obj_type_t {
@@ -321,6 +322,7 @@ extern const mp_obj_type_t mp_type_staticmethod;
 extern const mp_obj_type_t mp_type_classmethod;
 extern const mp_obj_type_t mp_type_property;
 extern const mp_obj_type_t mp_type_stringio;
+extern const mp_obj_type_t mp_type_bytesio;
 
 // Exceptions
 extern const mp_obj_type_t mp_type_BaseException;