Disabling syntax auto-complete

Is there an easy way to disable syntax autocomplete? It seems to not jive with the way I use the app.

For example, often I’ll paste some code and then wrap it with a code block. So I’ll paste, go up a line, and type

```ruby

But what actually comes out is

```ruby`

I’ve also run into issues with [ and ( autocompletion breaking my flow when trying to type code without specifying a code block.