case erlang:function_exported(rebar3, main, 1) of
    true ->
        %% rebar3
        CONFIG;
    false ->
        %% rebar 2.x or older
        NewConf = lists:keystore(deps_dir, 1, CONFIG, {deps_dir, "deps"}),
        Deps = [{lager, "2.*",
                 {git, "https://github.com/basho/lager.git", "3.0.2"}},
                {jiffy, "0.*",
                 {git, "https://github.com/davisp/jiffy.git", "0.11.3"}},
                {gun, "1.*",
                 {git, "https://github.com/ninenines/gun.git", "1.0.0-pre.1"}},
                {shotgun, "0.*",
                 {git, "https://github.com/inaka/shotgun.git", "0.2.2"}}
               ],
        lists:keystore(deps, 1, NewConf, {deps, Deps})
end.