1 files changed, 2 insertions, 0 deletions
diff --git a/py/modio.c b/py/modio.c
index b4d033238..0f4a4326c 100644
--- a/py/modio.c
+++ b/py/modio.c
@@ -147,6 +147,7 @@ STATIC mp_uint_t bufwriter_write(mp_obj_t self_in, const void *buf, mp_uint_t si
         buf = (byte*)buf + rem;
         size -= rem;
         mp_uint_t out_sz = mp_stream_write_exactly(self->stream, self->buf, self->alloc, errcode);
+        (void)out_sz;
         if (*errcode != 0) {
             return MP_STREAM_ERROR;
         }
@@ -165,6 +166,7 @@ STATIC mp_obj_t bufwriter_flush(mp_obj_t self_in) {
     if (self->len != 0) {
         int err;
         mp_uint_t out_sz = mp_stream_write_exactly(self->stream, self->buf, self->len, &err);
+        (void)out_sz;
         // TODO: try to recover from a case of non-blocking stream, e.g. move
         // remaining chunk to the beginning of buffer.
         assert(out_sz == self->len);