How to change indentation of lambdas for Erlang in spacemacs?

Question

No matter what I try I can't make lambdas indent with 4 spaces. They always land with 8:

fun() ->
        8
end

instead of desired

fun() ->
    4
end

I tried adding to my user config following variables:

(setq-default erlang-indent-level 4
              erlang-indent-guard 2
              erlang-argument-indent 2)

But it didn't make any difference. I also tried setvar and setq. How to force spacemacs to indent lambdas using 4 spaces?