diff --git a/.gitignore b/.gitignore
index 4c14464..4a8eee6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,5 @@ ebin
 *.plt
 erl_crash.dump
 .DS_Store
+doc
+.rebar
diff --git a/rebar.config b/rebar.config
index 38858b5..0dcef82 100644
--- a/rebar.config
+++ b/rebar.config
@@ -1,6 +1,5 @@
 {erl_opts, [
   % uncomment to always decode to maps
   % {d, maps_always},
-  {platform_define, "R14|R15", 'no_binary_to_whatever'},
-  {platform_define, "^((?!R1[456]).)*$", 'maps_support'}
-]}.
\ No newline at end of file
+]}.
+{edoc_opts, [{preprocess, true}]}.
\ No newline at end of file
diff --git a/rebar.config.script b/rebar.config.script
new file mode 100644
index 0000000..4510155
--- /dev/null
+++ b/rebar.config.script
@@ -0,0 +1,11 @@
+Def0 = case erlang:is_builtin(erlang, binary_to_integer, 1) andalso
+            erlang:is_builtin(erlang, binary_to_float, 1) of
+           true -> [];
+           false -> [{d, no_binary_to_whatever}]
+       end,
+Defs = case erlang:is_builtin(erlang, is_map, 1) of
+           true -> [{d, maps_support}|Def0];
+           false -> Def0
+       end,
+lists:keystore(erl_opts, 1, CONFIG,
+               {erl_opts, proplists:get_value(erl_opts, CONFIG, []) ++ Defs}).
diff --git a/src/jsx.erl b/src/jsx.erl
index 0401ce5..0b55b2e 100644
--- a/src/jsx.erl
+++ b/src/jsx.erl
@@ -67,23 +67,29 @@
 -type config() :: jsx_config:config().
 
 -spec encode(Source::json_term()) -> json_text().
--spec encode(Source::json_term(), Config::jsx_to_json:config()) -> json_text() | {incomplete, encoder()}.
 
 encode(Source) -> encode(Source, []).
+
+-spec encode(Source::json_term(), Config::jsx_to_json:config()) -> json_text() | {incomplete, encoder()}.
+
 encode(Source, Config) -> jsx_to_json:to_json(Source, Config).
 
 
 -spec decode(Source::json_text()) -> json_term().
--spec decode(Source::json_text(), Config::jsx_to_term:config()) -> json_term()  | {incomplete, decoder()}.
 
 decode(Source) -> decode(Source, []).
+
+-spec decode(Source::json_text(), Config::jsx_to_term:config()) -> json_term() | {incomplete, decoder()}.
+
 decode(Source, Config) -> jsx_to_term:to_term(Source, Config).
 
 
 -spec format(Source::json_text()) -> json_text().
--spec format(Source::json_text(), Config::jsx_to_json:config()) -> json_text() | {incomplete, decoder()}.
 
 format(Source) -> format(Source, []).
+
+-spec format(Source::json_text(), Config::jsx_to_json:config()) -> json_text() | {incomplete, decoder()}.
+
 format(Source, Config) -> jsx_to_json:format(Source, Config).
 
 
@@ -97,24 +103,30 @@ minify(Source) -> format(Source, []).
 prettify(Source) -> format(Source, [space, {indent, 2}]).
 
 
--spec is_json(Source::any()) -> true | false.
--spec is_json(Source::any(), Config::jsx_verify:config()) -> true | false | {incomplete, decoder()}.
+-spec is_json(Source::any()) -> boolean().
 
 is_json(Source) -> is_json(Source, []).
+
+-spec is_json(Source::any(), Config::jsx_verify:config()) -> boolean() | {incomplete, decoder()}.
+
 is_json(Source, Config) -> jsx_verify:is_json(Source, Config).
 
 
--spec is_term(Source::any()) -> true | false.
--spec is_term(Source::any(), Config::jsx_verify:config()) -> true | false | {incomplete, encoder()}.
+-spec is_term(Source::any()) -> boolean().
 
 is_term(Source) -> is_term(Source, []).
+
+-spec is_term(Source::any(), Config::jsx_verify:config()) -> boolean() | {incomplete, encoder()}.
+
 is_term(Source, Config) -> jsx_verify:is_term(Source, Config).
 
 
 -spec consult(File::file:name_all()) -> list(json_term()).
--spec consult(File::file:name_all(), Config::jsx_to_term:config()) -> list(json_term()).
 
 consult(File) -> consult(File, []).
+
+-spec consult(File::file:name_all(), Config::jsx_to_term:config()) -> list(json_term()).
+
 consult(File, Config) -> jsx_consult:consult(File, Config).
 
 
@@ -170,7 +182,7 @@ resume(Term, {parser, State, Handler, Stack}, Config) ->
     jsx_parser:resume(Term, State, Handler, Stack, jsx_config:parse_config(Config)).
 
 
--spec maps_support() -> true | false.
+-spec maps_support() -> boolean().
 
 -ifndef(maps_support).
 maps_support() -> false.
diff --git a/src/jsx_consult.erl b/src/jsx_consult.erl
index 0c9284e..2b0f1da 100644
--- a/src/jsx_consult.erl
+++ b/src/jsx_consult.erl
@@ -58,8 +58,6 @@
 -endif.
 
 
--spec consult(File::file:name_all(), Config::config()) -> [json_value()].
-
 -ifdef(maps_always).
 opts(Opts) -> [return_maps, multi_term] ++ Opts.
 -endif.
@@ -67,6 +65,8 @@ opts(Opts) -> [return_maps, multi_term] ++ Opts.
 opts(Opts) -> [multi_term] ++ Opts.
 -endif.
 
+-spec consult(File::file:name_all(), Config::config()) -> [json_value()].
+
 consult(File, Config) when is_list(Config) ->
     case file:read_file(File) of
       {ok, Bin}  ->
diff --git a/src/jsx_decoder.erl b/src/jsx_decoder.erl
index 07dce72..4600956 100644
--- a/src/jsx_decoder.erl
+++ b/src/jsx_decoder.erl
@@ -1010,8 +1010,7 @@ finish_number(Rest, Handler, Acc, Stack, Config) ->
 -ifndef(no_binary_to_whatever).
 format_number({integer, Acc}) -> {integer, binary_to_integer(Acc)};
 format_number({float, Acc}) -> {float, binary_to_float(Acc)}.
--endif.
--ifdef(no_binary_to_whatever).
+-else.
 format_number({integer, Acc}) -> {integer, list_to_integer(unicode:characters_to_list(Acc))};
 format_number({float, Acc}) -> {float, list_to_float(unicode:characters_to_list(Acc))}.
 -endif.