diff --git a/README.md b/README.md
index 7290861..abcca87 100644
--- a/README.md
+++ b/README.md
@@ -19,8 +19,10 @@ Function           | Description
 `parse/2`          | Parse a URI, returning the result as either a `uri()` or `url()`.
 `percent_decode/1` | Decode a percent encoded string value.
 `percent_encode/1` | Percent encode a string value.
+`percent_encode/2` | Percent encode a string value, explicitly stating the desired case for hexidecimal values. Pass `uppercase` to the second value to have hex values returned as `%2F` instead of `%2f`.
 `plus_decode/1`    | Decode a percent encoded string value that uses pluses for spaces.
 `plus_encode/1`    | Percent encode a string value similar to `percent_encode/1`, but encodes spaces with a plus (`+`) instead of `%20`.
+`plus_encode/2`    | Percent encode a string value similar to `percent_encode/1`, but encodes spaces with a plus (`+`) instead of `%20`, explicitly stating the desired case for hexidecimal values. Pass `uppercase` to the second value to have hex values returned as `%2F` instead of `%2f`.
 
 ### Types
 
diff --git a/src/urilib.app.src b/src/urilib.app.src
index aacf95c..59b3bad 100644
--- a/src/urilib.app.src
+++ b/src/urilib.app.src
@@ -1,6 +1,6 @@
 {application, urilib, [
   {description, "A RFC-3986 URI Library for parsing and building URIs"},
-  {vsn,"0.1.1"},
+  {vsn,"0.2.0"},
   {licenses, ["BSD"]},
   {links, [{"Github", "https://github.com/gmr/urilib"}]},
   {maintainers, ["Gavin M. Roy"]},
@@ -11,6 +11,6 @@
     inets,
     edoc
   ]},
-  {mod, {urilib, []}},
+  {modules, []},
   {env, []}
 ]}.
diff --git a/src/urilib.erl b/src/urilib.erl
index ad09f88..bc9e8a3 100644
--- a/src/urilib.erl
+++ b/src/urilib.erl
@@ -11,8 +11,10 @@
          parse/2,
          percent_decode/1,
          percent_encode/1,
+         percent_encode/2,
          plus_decode/1,
-         plus_encode/1]).
+         plus_encode/1,
+         plus_encode/2]).
 
 -export_type([scheme/0,
               host/0,
@@ -32,6 +34,7 @@
 -compile(export_all).
 -endif.
 
+-type hexcase() :: uppercase | lowercase.
 -type scheme() :: http | https | atom().
 -type host() :: string().
 -type tcp_port() :: integer().
@@ -45,7 +48,6 @@
 -type uri() :: {scheme(), authority(), path(), query(), fragment()}.
 -type url() :: {scheme(), username(), password(), host(), tcp_port(), path(), query(), fragment()}.
 
-
 -spec build(Value :: uri() | url()) -> string().
 %% @doc Build a URI
 %% @end
@@ -101,12 +103,27 @@ parse(Value, url) ->
 
 
 -spec percent_encode(string()) -> string().
-%% @doc Percent encode a string value.
+%% @doc Percent encode a string value. Note that this will return hexidecimal
+%% values in lowercase. If you need uppercase values, invoke percent_encode/2
+%% with the second parameter as the value ``upercase``.
 %% @end
 percent_encode(Value) ->
     edoc_lib:escape_uri(Value).
 
 
+-spec percent_encode(string(), hexcase()) -> string().
+%% @doc Percent encode a string value.
+%%
+%% When lowercase is passed, hexidecimal strings with A-F values in them are returned
+%% as lowercase. Likewise, the uppercase value will encode hexidecimal strings as
+%% uppercase values.
+%% @end
+percent_encode(Value, lowercase) ->
+    percent_encode(Value);
+percent_encode(Value, uppercase) ->
+    hex_to_upper(percent_encode(Value)).
+
+
 -spec percent_decode(string()) -> string().
 %% @doc Decode a percent encoded string value.
 %% @end
@@ -124,6 +141,21 @@ plus_encode(Value) ->
     string:join([edoc_lib:escape_uri(V) || V <- string:tokens(Value, " ")], "+").
 
 
+-spec plus_encode(string(), hexcase()) -> string().
+%% @doc Percent encode a string value similar to encode/1, but encodes spaces with a
+%% plus (`+') instead of `%20'. This function can be used for encoding query arguments.
+%% When lowercase is passed, hexidecimal strings with A-F values in them are returned
+%% as lowercase. Likewise, the uppercase value will encode hexidecimal strings as
+%% uppercase values.
+%%
+%% Note: The use of plus for space is defined in RFC-1630 but does not appear in RFC-3986.
+%% @end
+plus_encode(Value, lowercase) ->
+    plus_encode(Value);
+plus_encode(Value, uppercase) ->
+    hex_to_upper(plus_encode(Value)).
+
+
 -spec plus_decode(string()) -> string().
 %% @doc Decode a percent encoded string value that uses pluses for spaces.
 %%
@@ -284,3 +316,21 @@ url_maybe_add_fragment(Value, URL) ->
         _ -> edoc_lib:escape_uri(Value)
     end,
     string:join([URL, Fragment], "#").
+
+
+-spec hex_to_upper(string()) -> string().
+%% @private
+hex_to_upper(Value) ->
+    hex_to_upper(Value, [], []).
+hex_to_upper([], [], Value) ->
+    Value;
+hex_to_upper([], Hex, Value) ->
+    lists:append(Value, string:to_upper(Hex));
+hex_to_upper([37|T], [], Value) ->
+    hex_to_upper(T, [37], Value);
+hex_to_upper([H|T], [], Value) ->
+    hex_to_upper(T, [], lists:append(Value, [H]));
+hex_to_upper(Remaining, Hex, Value) when length(Hex) == 3 ->
+    hex_to_upper(Remaining, [], lists:append(Value, string:to_upper(Hex)));
+hex_to_upper([H|T], Hex, Value) ->
+    hex_to_upper(T, lists:append(Hex, [H]), Value).
diff --git a/test/urilib_tests.erl b/test/urilib_tests.erl
index 7072878..3c5f84a 100644
--- a/test/urilib_tests.erl
+++ b/test/urilib_tests.erl
@@ -2,6 +2,11 @@
 
 -include_lib("eunit/include/eunit.hrl").
 
+hex_to_upper_test() ->
+    Value = "%2f%c0%88this+is+%c3%a4n+%c3%aaxample+value+woot%c0%88%2f",
+    Expect = "%2F%C0%88this+is+%C3%A4n+%C3%AAxample+value+woot%C0%88%2F",
+    ?assertEqual(Expect, urilib:hex_to_upper(Value)).
+
 build_variation1_test() ->
     Params = {amqp, {{"guest", "password"}, "rabbitmq", 5672}, "/%2f", [{"heartbeat", "5"}], undefined},
     Expect = "amqp://guest:password@rabbitmq:5672/%2f?heartbeat=5",
@@ -147,7 +152,32 @@ percent_encode_unicode_test() ->
     Expect = "foo%2fbar%c0%88baz",
     ?assertEqual(Expect, urilib:percent_encode(Value)).
 
+percent_encode_lowercase_unicode_test() ->
+    Value = "/✈this is än êxample value woot✈/",
+    Expect = "%2f%c0%88this%20is%20%c3%a4n%20%c3%aaxample%20value%20woot%c0%88%2f",
+    ?assertEqual(Expect, urilib:percent_encode(Value, lowercase)).
+
+percent_encode_uppercase_unicode_test() ->
+    Value = "/✈this is än êxample value woot✈/",
+    Expect = "%2F%C0%88this%20is%20%C3%A4n%20%C3%AAxample%20value%20woot%C0%88%2F",
+    ?assertEqual(Expect, urilib:percent_encode(Value, uppercase)).
+
+percent_encode_uppercase_perent_test() ->
+    Value = "/✈this is än êxample value woot with 30% off✈/",
+    Expect = "%2F%C0%88this+is+%C3%A4n+%C3%AAxample+value+woot+with+30%25+off%C0%88%2F",
+    ?assertEqual(Expect, urilib:plus_encode(Value, uppercase)).
+
 plus_encode_test() ->
     Value = "foo/bar baz",
     Expect = "foo%2fbar+baz",
     ?assertEqual(Expect, urilib:plus_encode(Value)).
+
+plus_encode_lowercase_test() ->
+    Value = "/✈this is än êxample value woot✈/",
+    Expect = "%2f%c0%88this+is+%c3%a4n+%c3%aaxample+value+woot%c0%88%2f",
+    ?assertEqual(Expect, urilib:plus_encode(Value, lowercase)).
+
+plus_encode_uppercase_test() ->
+    Value = "/✈this is än êxample value woot✈/",
+    Expect = "%2F%C0%88this+is+%C3%A4n+%C3%AAxample+value+woot%C0%88%2F",
+    ?assertEqual(Expect, urilib:plus_encode(Value, uppercase)).