diff --git a/py/runtime.c b/py/runtime.c
index b4d5250e83..6d8eddedc8 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -40,6 +40,7 @@
 #include "py/objmodule.h"
 #include "py/objgenerator.h"
 #include "py/smallint.h"
+#include "py/stream.h"
 #include "py/runtime.h"
 #include "py/builtin.h"
 #include "py/stackctrl.h"
@@ -1327,7 +1328,6 @@ mp_obj_t mp_getiter(mp_obj_t o_in, mp_obj_iter_buf_t *iter_buf) {
 
 STATIC mp_fun_1_t type_get_iternext(const mp_obj_type_t *type) {
     if ((type->flags & MP_TYPE_FLAG_ITER_IS_STREAM) == MP_TYPE_FLAG_ITER_IS_STREAM) {
-        mp_obj_t mp_stream_unbuffered_iter(mp_obj_t self);
         return mp_stream_unbuffered_iter;
     } else if (type->flags & MP_TYPE_FLAG_ITER_IS_ITERNEXT) {
         return (mp_fun_1_t)MP_OBJ_TYPE_GET_SLOT(type, iter);