Ah, for those, I think we can just compile the module passing `no_warn_missing_spec` or `warn_missing_spec, false` (I am not sure which would work). Those modules are internal, they will never have user code anyway. Note we do something similar for native: https://github.com/bitwalker/elixir/blob/please-the-dialyzer-gods/lib/elixir/src/elixir_compiler.erl#L71