diff --git a/README.md b/README.md
index 107e898..db3b6f7 100644
--- a/README.md
+++ b/README.md
@@ -59,8 +59,8 @@ depending on your preferred shell.
 
 ## Usage
 
-The most common use case is to `cd` into a folder containing an `elvis.config` file
-and executing `elvis rock`.
+The most common use case is to `cd` into a folder (containing an `elvis.config` file, or not -
+in which case some sane defaults apply) and execute `elvis rock`.
 
 If you just execute `elvis` with no arguments or options you'll get to the usage instructions
 outlined in this README.
@@ -97,7 +97,7 @@ in the configuration (i.e. either `elvis.config` or the path set by option `--co
 
 ### `--config <file>` (`-c <file>`)
 
-Allows providing the path to the config. file (by default `elvis.config` is assumed).
+Allows providing the path to the configuration file (by default `elvis.config` is assumed).
 
 ### `--help` (`-h`)
 
diff --git a/config/elvis-test.config b/config/elvis-test.config
index 74465bb..a711af3 100644
--- a/config/elvis-test.config
+++ b/config/elvis-test.config
@@ -7,17 +7,9 @@
         filter => "*.erl",
         ruleset => erl_files
        },
-      #{dirs => ["../.."],
-        filter => "Makefile",
-        ruleset => makefiles
-       },
       #{dirs => ["../.."],
         filter => "rebar.config",
         ruleset => rebar_config
-       },
-      #{dirs => ["../.."],
-        filter => "elvis.config",
-        ruleset => elvis_config
        }
      ]
     }
diff --git a/config/elvis.config b/config/elvis.config
index 74c730c..04f7b2f 100644
--- a/config/elvis.config
+++ b/config/elvis.config
@@ -7,17 +7,9 @@
         filter => "*.erl",
         ruleset => erl_files
        },
-      #{dirs => ["."],
-        filter => "Makefile",
-        ruleset => makefiles
-       },
       #{dirs => ["."],
         filter => "rebar.config",
         ruleset => rebar_config
-       },
-      #{dirs => ["."],
-        filter => "elvis.config",
-        ruleset => elvis_config
        }
      ]
     }
diff --git a/config/test.config b/config/test.config
index d55bf42..d298ab6 100644
--- a/config/test.config
+++ b/config/test.config
@@ -7,17 +7,9 @@
         filter => "**.erl",
         ruleset => erl_files
        },
-      #{dirs => ["."],
-        filter => "Makefile",
-        ruleset => makefiles
-       },
-      #{dirs => ["."],
+      #{dirs => ["../.."],
         filter => "rebar.config",
         ruleset => rebar_config
-       },
-      #{dirs => ["."],
-        filter => "elvis.config",
-        ruleset => elvis_config
        }
      ]
     },
diff --git a/elvis.config b/elvis.config
index 971053a..320e854 100644
--- a/elvis.config
+++ b/elvis.config
@@ -5,7 +5,4 @@
        ruleset => erl_files},
      #{dirs => ["."],
        filter => "rebar.config",
-       ruleset => rebar_config},
-     #{dirs => ["."],
-       filter => "elvis.config",
-       ruleset => elvis_config}]}]}].
+       ruleset => rebar_config}]}]}].
diff --git a/rebar.config b/rebar.config
index 41a226f..5ccdf8d 100644
--- a/rebar.config
+++ b/rebar.config
@@ -24,7 +24,11 @@
 
 %% == Dependencies and plugins ==
 
-{deps, [{elvis_core, "4.1.1"}, {getopt, "1.0.3"}, {egithub, "0.7.0"}]}.
+{deps,
+ [{elvis_core,
+   {git, "https://github.com/inaka/elvis_core.git", {branch, "fix/config-parse-validate"}}},
+  {getopt, "1.0.3"},
+  {egithub, "0.7.0"}]}.
 
 {project_plugins,
  [{rebar3_hank, "~> 1.4.1"},
@@ -36,7 +40,7 @@
 
 {ex_doc,
  [{source_url, <<"https://github.com/inaka/elvis">>},
-  {extras, [<<"README.md">>, <<"LICENSE">>]},
+  {extras, [<<"README.md">>, <<"LICENSE">>, <<"CONTRIBUTING.md">>]},
   {main, <<"README.md">>},
   {prefix_ref_vsn_with_v, false},
   {api_reference, false}]}.
diff --git a/rebar.lock b/rebar.lock
index 990854c..9b7943e 100644
--- a/rebar.lock
+++ b/rebar.lock
@@ -1,7 +1,10 @@
 {"1.2.0",
 [{<<"certifi">>,{pkg,<<"certifi">>,<<"2.15.0">>},2},
  {<<"egithub">>,{pkg,<<"egithub">>,<<"0.7.0">>},0},
- {<<"elvis_core">>,{pkg,<<"elvis_core">>,<<"4.1.1">>},0},
+ {<<"elvis_core">>,
+  {git,"https://github.com/inaka/elvis_core.git",
+       {ref,"5ae29ef4f9361fd8232a77a037a977ad8b7dc736"}},
+  0},
  {<<"getopt">>,{pkg,<<"getopt">>,<<"1.0.3">>},0},
  {<<"goldrush">>,{pkg,<<"goldrush">>,<<"0.1.9">>},1},
  {<<"hackney">>,{pkg,<<"hackney">>,<<"1.17.1">>},1},
@@ -19,7 +22,6 @@
 {pkg_hash,[
  {<<"certifi">>, <<"0E6E882FCDAAA0A5A9F2B3DB55B1394DBA07E8D6D9BCAD08318FB604C6839712">>},
  {<<"egithub">>, <<"CFF720B2ADE8A0528B8861D2309339FD3C1C289B9BCB9E498FF77C619CE28AF2">>},
- {<<"elvis_core">>, <<"0F69E9F1512C1EA68C65ABC805079DC3A5B22E0E16E0DE8DDDBB780A43D007A9">>},
  {<<"getopt">>, <<"4F3320C1F6F26B2BEC0F6C6446B943EB927A1E6428EA279A1C6C534906EE79F1">>},
  {<<"goldrush">>, <<"F06E5D5F1277DA5C413E84D5A2924174182FB108DABB39D5EC548B27424CD106">>},
  {<<"hackney">>, <<"08463F93D2CC1A03817BF28D8DAE6021543F773BD436C9377047224856C4422C">>},
@@ -36,7 +38,6 @@
 {pkg_hash_ext,[
  {<<"certifi">>, <<"B147ED22CE71D72EAFDAD94F055165C1C182F61A2FF49DF28BCC71D1D5B94A60">>},
  {<<"egithub">>, <<"E009CE11EFD8008D0F9ED59D9C488E3E9ABE302A0F2CD6D663E4CC26756FCC4C">>},
- {<<"elvis_core">>, <<"80A562574B8D974A2E7544E9A9455716D04C9E095DBC8C8915E2468031DD1385">>},
  {<<"getopt">>, <<"7E01DE90AC540F21494FF72792B1E3162D399966EBBFC674B4CE52CB8F49324F">>},
  {<<"goldrush">>, <<"99CB4128CFFCB3227581E5D4D803D5413FA643F4EB96523F77D9E6937D994CEB">>},
  {<<"hackney">>, <<"D2CBA9E3C8103AD0320623E9F1C33E8D378A15EAABE2EE8AE441898F3D35A18C">>},
diff --git a/src/elvis.app.src b/src/elvis.app.src
index dcf341e..55a0a9e 100644
--- a/src/elvis.app.src
+++ b/src/elvis.app.src
@@ -5,17 +5,6 @@
   {vsn, git},
   {applications, [kernel, stdlib, ssl, elvis_core, egithub, katana_code, getopt]},
   {modules, [elvis, elvis_git, elvis_webhook]},
-  {env,
-   [{config,
-     [#{dirs => ["apps/**", "lib/**", "src/**", "test/**"],
-        filter => "*.erl",
-        ruleset => erl_files},
-      #{dirs => ["."],
-        filter => "Makefile",
-        ruleset => makefiles},
-      #{dirs => [".", "apps/**", "lib/**", "src/**"],
-        filter => "rebar.config",
-        ruleset => rebar_config}]}]},
   {registered, []},
   {licenses, ["Apache 2.0"]},
   {links,
diff --git a/src/elvis.erl b/src/elvis.erl
index 6d4e153..e0c8d3c 100644
--- a/src/elvis.erl
+++ b/src/elvis.erl
@@ -8,10 +8,6 @@
 
 -export([start/0]).
 
--define(APP_NAME, "elvis").
--define(DEFAULT_CONFIG_PATH, "./elvis.config").
--define(DEFAULT_REBAR_CONFIG_PATH, "./rebar.config").
-
 -type option() ::
     commands |
     help |
@@ -61,7 +57,7 @@ main(Args) ->
         {ok, {Options, Commands}} ->
             process_options(Options, Commands);
         {error, {Reason, Data}} ->
-            elvis_utils:error_prn("~s ~p~n", [Reason, Data]),
+            elvis_utils:error("~s ~p~n", [Reason, Data]),
             help(),
             elvis_utils:erlang_halt(1)
     end.
@@ -110,12 +106,12 @@ process_options(Options, Commands) ->
         process_options(Options, AtomCommands, Config)
     catch
         _:Exception ->
-            elvis_utils:error_prn("~p.", [Exception]),
+            elvis_utils:error("~p.", [Exception]),
             elvis_utils:erlang_halt(1)
     end.
 
 %% @private
--spec process_options([option()], [string()], elvis_config:configs()) -> ok.
+-spec process_options([option()], [string()], [elvis_config:t()]) -> ok.
 process_options([help | Opts], Cmds, Config) ->
     help(),
     process_options(Opts, Cmds, Config);
@@ -126,16 +122,16 @@ process_options([commands | Opts], Cmds, Config) ->
     commands(),
     process_options(Opts, Cmds, Config);
 process_options([{output_format, Format} | Opts], Cmds, Config) ->
-    ok = application:set_env(elvis_core, output_format, list_to_atom(Format)),
+    ok = elvis_config:set_output_format(list_to_atom(Format)),
     process_options(Opts, Cmds, Config);
 process_options([keep_rocking | Opts], Cmds, Config) ->
-    ok = application:set_env(elvis_core, keep_rocking, true),
+    ok = application:set_env(elvis, keep_rocking, true),
     process_options(Opts, Cmds, Config);
 process_options([quiet | Opts], Cmds, Config) ->
-    ok = application:set_env(elvis_core, no_output, true),
+    ok = elvis_config:set_no_output(true),
     process_options(Opts, Cmds, Config);
 process_options([verbose | Opts], Cmds, Config) ->
-    ok = application:set_env(elvis_core, verbose, true),
+    ok = elvis_config:set_verbose(true),
     process_options(Opts, Cmds, Config);
 process_options([version | Opts], Cmds, Config) ->
     version(),
@@ -150,7 +146,7 @@ process_options([{parallel, Num} | Opts], Cmds, Config) ->
             _ ->
                 erlang:list_to_integer(Num)
         end,
-    ok = application:set_env(elvis_core, parallel, N),
+    ok = elvis_config:set_parallel(N),
     process_options(Opts, Cmds, Config);
 process_options([], Cmds, Config) ->
     process_commands(Cmds, Config).
@@ -162,7 +158,7 @@ process_options([], Cmds, Config) ->
                         'git-hook' |
                         'git-branch' |
                         string()],
-                       elvis_config:configs()) ->
+                       [elvis_config:t()]) ->
                           ok.
 process_commands([rock | Files], Config) ->
     case Files of
@@ -199,10 +195,10 @@ process_commands([_Cmd | _Cmds], _Config) ->
 -spec help() -> ok.
 help() ->
     OptSpecList = option_spec_list(),
-    getopt:usage(OptSpecList, ?APP_NAME, standard_io).
+    getopt:usage(OptSpecList, "elvis", standard_io).
 
 %% @private
--spec help(elvis_config:configs()) -> elvis_config:configs().
+-spec help([elvis_config:t()]) -> [elvis_config:t()].
 help(Config) ->
     help(),
     Config.
@@ -250,7 +246,7 @@ rock_one_song(FileName, Config) ->
     F = atom_to_list(FileName),
     case elvis_core:rock_this(F, Config) of
         {fail, _} ->
-            case application:get_env(elvis_core, keep_rocking, false) of
+            case application:get_env(elvis, keep_rocking, false) of
                 false ->
                     elvis_utils:erlang_halt(1);
                 true ->
@@ -260,27 +256,15 @@ rock_one_song(FileName, Config) ->
             ok
     end.
 
-%% @private
--spec default_config() -> elvis_config:configs().
+-spec default_config() -> [elvis_config:t()].
 default_config() ->
-    default_config([fun() -> elvis_config:from_file(?DEFAULT_CONFIG_PATH) end,
-                    fun() -> elvis_config:from_rebar(?DEFAULT_REBAR_CONFIG_PATH) end]).
-
--spec default_config([Fun]) -> elvis_config:configs()
-    when Fun :: fun(() -> elvis_config:config()).
-default_config([Fun | Funs]) ->
-    Config =
-        try
-            Fun()
-        catch
-            _:_ ->
-                []
-        end,
-    case Config of
-        [] ->
-            default_config(Funs);
+    case elvis_config:config() of
+        {fail, [{throw, {invalid_config, _}}]} ->
+            % When we implement warnings_as_errors, where the default is false,
+            % replace the next line with elvis_config:default() alone
+            % Maybe think about making this the default for `elvis_config:config()`
+            % with an output notice
+            application:get_env(elvis, config, elvis_config:default());
         Config ->
             Config
-    end;
-default_config([]) ->
-    application:get_env(elvis, config, []).
+    end.
diff --git a/src/elvis_git.erl b/src/elvis_git.erl
index b947d31..218e35e 100644
--- a/src/elvis_git.erl
+++ b/src/elvis_git.erl
@@ -12,7 +12,7 @@
 %%% Public
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
--spec run_hook(elvis_config:configs()) -> ok.
+-spec run_hook([elvis_config:t()]) -> ok.
 run_hook(Config) ->
     Files = elvis_git:staged_files(),
     NewConfig = elvis_config:resolve_files(Config, Files),
@@ -23,7 +23,7 @@ run_hook(Config) ->
             ok
     end.
 
--spec run_branch(string(), elvis_config:configs()) -> ok.
+-spec run_branch(string(), [elvis_config:t()]) -> ok.
 run_branch(Commit, Config) ->
     Files = elvis_git:branch_files(Commit),
     NewConfig = elvis_config:resolve_files(Config, Files),
@@ -34,11 +34,11 @@ run_branch(Commit, Config) ->
             ok
     end.
 
--spec branch_files(string()) -> [elvis_file:file()].
+-spec branch_files(string()) -> [elvis_file:t()].
 branch_files(Commit) ->
     process_files(?LIST_BRANCH_CHANGES(Commit)).
 
--spec staged_files() -> [elvis_file:file()].
+-spec staged_files() -> [elvis_file:t()].
 staged_files() ->
     process_files(?LIST_STAGED).
 
@@ -49,7 +49,7 @@ process_files(Cmd) ->
     Paths = [binary_to_list(Path) || Path <- Lines, byte_size(Path) > 0],
     lists:map(fun elvis_file/1, Paths).
 
--spec elvis_file(string()) -> elvis_file:file().
+-spec elvis_file(string()) -> elvis_file:t().
 elvis_file(Path) ->
     #{path => Path}.
 
@@ -79,11 +79,10 @@ install_hook() ->
         check_git_dir(),
         ok = filelib:ensure_dir(?PRE_COMMIT_FILE),
         _ = add_pre_commit_hook(),
-        elvis_utils:info("Elvis pre-commit hook installed. "
-                         "Wop-bop-a-loom-a-blop-bam-boom!")
+        elvis_utils:info("Elvis pre-commit hook installed. Wop-bop-a-loom-a-blop-bam-boom!", [])
     catch
         _:Reason ->
-            elvis_utils:error_prn(Reason)
+            elvis_utils:error(Reason, [])
     end.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
diff --git a/test/elvis_meta_SUITE.erl b/test/elvis_meta_SUITE.erl
deleted file mode 100644
index ec26cc9..0000000
--- a/test/elvis_meta_SUITE.erl
+++ /dev/null
@@ -1,30 +0,0 @@
--module(elvis_meta_SUITE).
-
--export([all/0]).
--export([elvis/1]).
-
--type config() :: proplists:proplist().
-
--export_type([config/0]).
-
--hank([unnecessary_function_arguments]).
-
--spec all() -> [elvis, ...].
-all() ->
-    [elvis].
-
--spec elvis(config()) -> {comment, []}.
-elvis(_Config) ->
-    BaseDir = code:lib_dir(elvis),
-    ConfigFile = filename:join(BaseDir, "../../../../elvis.config"),
-    ElvisConfig = [fix_dirs(Group) || Group <- elvis_config:from_file(ConfigFile)],
-    ct:comment("Elvis rocks!"),
-    ok = elvis_core:rock(ElvisConfig),
-    {comment, ""}.
-
-fix_dirs(#{dirs := Dirs} = Group) ->
-    NewDirs =
-        [filename:join(
-             code:lib_dir(elvis), Dir)
-         || Dir <- Dirs],
-    Group#{dirs := NewDirs}.
diff --git a/test/examples/user_defined_rules.erl b/test/examples/user_defined_rules.erl
index c203bd1..cee9e6d 100644
--- a/test/examples/user_defined_rules.erl
+++ b/test/examples/user_defined_rules.erl
@@ -1,9 +1,9 @@
 -module(user_defined_rules).
 
--export([rule/3]).
+-export([rule/2]).
 
 -hank([unnecessary_function_arguments]).
 
--spec rule(any(), any(), any()) -> [elvis_result:item(), ...].
-rule(_Config, _Target, _) ->
+-spec rule(any(), any()) -> [elvis_result:item(), ...].
+rule(_Config, _Target) ->
     [elvis_result:new(item, "This will always FAIL.", [], 1)].