1 files changed, 1 insertions, 1 deletions
diff --git a/buf.c b/buf.c
index b22ff2b2..6a5ed15b 100644
--- a/buf.c
+++ b/buf.c
@@ -228,7 +228,7 @@ static void buf_put_bytes(val buf, val pos, mem_t *ptr, cnum size, val self)
 {
   struct buf *b = buf_handle(buf, self);
   cnum p = buf_check_index(pos, self);
-  val req_len = plus(pos, num_fast(size));
+  val req_len = plus(pos, num(size));
   if (gt(req_len, b->len))
     buf_do_set_len(buf, b, req_len, nil, self);
   memcpy(b->data + p, ptr, size);