diff --git a/.travis.yml b/.travis.yml
index 35c5897..efd1082 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,11 @@
-language: erlang
+=nlanguage: erlang
 otp_release:
        - R15B02
        - R15B01
        - R15B
-
+       - R14B04
+       - R14B03
+       - R14B02
 before_script: "make get-deps"
 script: "make"
 branches:
diff --git a/Makefile b/Makefile
index ab8b307..538bc3e 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,7 @@ $(ERLWARE_COMMONS_PLT):
 	   --apps erts kernel stdlib eunit -r deps
 
 dialyzer: $(ERLWARE_COMMONS_PLT)
-	dialyzer --fullpath --plt $(ERLWARE_COMMONS_PLT) -Wrace_conditions --src src
+	dialyzer --fullpath --plt $(ERLWARE_COMMONS_PLT) -Wrace_conditions -r ./ebin
 
 typer:
 	typer --plt $(ERLWARE_COMMONS_PLT) -r ./src
@@ -64,4 +64,4 @@ distclean: clean
 	rm -rf $(ERLWARE_COMMONS_PLT)
 	rm -rvf $(CURDIR)/deps/*
 
-rebuild: distclean all
+rebuild: distclean get-deps all
diff --git a/rebar.config b/rebar.config
index 08863d2..57dc49a 100644
--- a/rebar.config
+++ b/rebar.config
@@ -3,7 +3,7 @@
 %% Dependencies ================================================================
 {deps, [{neotoma, "",
          {git, "https://github.com/seancribbs/neotoma.git", {branch, master}}},
-        {proper, "", {git, "https://github.com/manopapad/proper.git", {branch, master}}},
+        {proper, "", {git, "https://github.com/bkearns/proper.git", {branch, master}}},
         {rebar_vsn_plugin, ".*", {git, "https://github.com/erlware/rebar_vsn_plugin.git",
                                   {branch, "master"}}}]}.
 
diff --git a/rebar.config.script b/rebar.config.script
new file mode 100644
index 0000000..1d5996c
--- /dev/null
+++ b/rebar.config.script
@@ -0,0 +1,15 @@
+{match, [ErtsNumber]} = re:run("R15B02", "R(\\d+).+", [{capture, [1], list}]),
+ErtsVsn = erlang:list_to_integer(ErtsNumber),
+Opts1 = case lists:keysearch(erl_opts, 1, CONFIG) of
+            {value, {erl_opts, Opts0}} ->
+                Opts0;
+            false ->
+                []
+        end,
+Opts2 = if
+            ErtsVsn >= 15 ->
+                [{d, have_callback_support} | Opts1];
+            true ->
+                Opts1
+        end,
+lists:keystore(erl_opts, 1, CONFIG, {erl_opts, Opts2}).
diff --git a/src/ec_compile.erl b/src/ec_compile.erl
index 482bdb3..6c15520 100644
--- a/src/ec_compile.erl
+++ b/src/ec_compile.erl
@@ -13,9 +13,11 @@
          erl_source_to_core_ast/1,
          erl_source_to_erl_ast/1,
          erl_source_to_asm/1,
+         erl_source_to_erl_syntax/1,
          erl_string_to_core_ast/1,
          erl_string_to_erl_ast/1,
-         erl_string_to_asm/1]).
+         erl_string_to_asm/1,
+         erl_string_to_erl_syntax/1]).
 
 %%%===================================================================
 %%% API
@@ -33,13 +35,13 @@
 beam_to_erl_source(BeamFName, ErlFName) ->
   case beam_lib:chunks(BeamFName, [abstract_code]) of
     {ok, {_, [{abstract_code, {raw_abstract_v1,Forms}}]}} ->
-      Src =
-        erl_prettypr:format(erl_syntax:form_list(tl(Forms))),
-        {ok, Fd} = file:open(ErlFName, [write]),
-        io:fwrite(Fd, "~s~n", [Src]),
-        file:close(Fd);
-    Error ->
-       Error
+          Src =
+              erl_prettypr:format(erl_syntax:form_list(tl(Forms))),
+          {ok, Fd} = file:open(ErlFName, [write]),
+          io:fwrite(Fd, "~s~n", [Src]),
+          file:close(Fd);
+      Error ->
+          Error
   end.
 
 %% @doc compile an erlang source file into a Core Erlang AST
@@ -67,6 +69,15 @@ erl_source_to_asm(Path) ->
     {ok, Contents} = file:read_file(Path),
     erl_string_to_asm(binary_to_list(Contents)).
 
+%% @doc compile an erlang source file to a string that displays the
+%% 'erl_syntax1 calls needed to reproduce those terms.
+%%
+%% @param Path - The path to the erlang source file
+-spec erl_source_to_erl_syntax(file:filename()) -> string().
+erl_source_to_erl_syntax(Path) ->
+    {ok, Contents} = file:read_file(Path),
+    erl_string_to_erl_syntax(Contents).
+
 %% @doc compile a string representing an erlang expression into an
 %% Erlang AST
 %%
@@ -105,3 +116,16 @@ erl_string_to_core_ast(StringExpr) ->
 -spec erl_string_to_asm(string()) -> ErlangAsm::term().
 erl_string_to_asm(StringExpr) ->
     compile:forms(erl_string_to_erl_ast(StringExpr), ['S']).
+
+%% @doc compile an erlang source file to a string that displays the
+%% 'erl_syntax1 calls needed to reproduce those terms.
+%%
+%% @param StringExpr - The string representing the erlang code.
+-spec erl_string_to_erl_syntax(string() | binary()) -> string().
+erl_string_to_erl_syntax(BinaryExpr)
+  when erlang:is_binary(BinaryExpr) ->
+    erlang:binary_to_list(BinaryExpr);
+erl_string_to_erl_syntax(StringExpr) ->
+    {ok, Tokens, _} = erl_scan:string(StringExpr),
+    {ok, ErlAST} = erl_parse:parse_form(Tokens),
+    io:format(erl_prettypr:format(erl_syntax:meta(ErlAST))).
diff --git a/src/ec_date.erl b/src/ec_date.erl
index 8d79c34..16a0af7 100644
--- a/src/ec_date.erl
+++ b/src/ec_date.erl
@@ -42,9 +42,11 @@
 -type hour() :: 0..23.
 -type minute() :: 0..59.
 -type second() :: 0..59.
+-type microsecond() :: 0..1000000.
+
 -type daynum() :: 1..7.
 -type date() :: {year(),month(),day()}.
--type time() :: {hour(),minute(),second()}.
+-type time() :: {hour(),minute(),second()} |{hour(),minute(),second(), microsecond()}.
 -type datetime() :: {date(),time()}.
 -type now() :: {integer(),integer(),integer()}.
 
@@ -59,8 +61,9 @@ format(Format) ->
 
 -spec format(string(),datetime() | now()) -> string().
 %% @doc format Date as Format
-format(Format, {_,_,_}=Now) ->
-    format(Format, calendar:now_to_datetime(Now), []);
+format(Format, {_,_,Ms}=Now) ->
+    {Date,{H,M,S}} = calendar:now_to_datetime(Now),
+    format(Format, {Date, {H,M,S,Ms}}, []);
 format(Format, Date) ->
     format(Format, Date, []).
 
@@ -70,6 +73,7 @@ parse(Date) ->
     do_parse(Date, calendar:universal_time(),[]).
 
 -spec parse(string(),datetime() | now()) -> datetime().
+
 %% @doc parses the datetime from a string
 parse(Date, {_,_,_}=Now) ->
     do_parse(Date, calendar:now_to_datetime(Now), []);
@@ -88,22 +92,61 @@ do_parse(Date, Now, Opts) ->
                 true -> {D1, T1};
                 false -> erlang:throw({?MODULE, {bad_date, Date}})
             end;
-        _ -> erlang:throw({?MODULE, {bad_date, Date}})
+        {D1, _T1, {Ms}} = {{Y, M, D}, {H, M1, S},  {Ms}}
+        when is_number(Y), is_number(M),
+             is_number(D), is_number(H),
+             is_number(M1), is_number(S),
+	     is_number(Ms) ->
+            case calendar:valid_date(D1) of
+                true -> {D1, {H,M1,S,Ms}};
+                false -> erlang:throw({?MODULE, {bad_date, Date}})
+            end;
+        Unknown -> erlang:throw({?MODULE, {bad_date, Date, Unknown }})
     end.
 
 -spec nparse(string()) -> now().
 %% @doc parses the datetime from a string into 'now' format
 nparse(Date) ->
-    DateTime = parse(Date),
-    GSeconds = calendar:datetime_to_gregorian_seconds(DateTime),
-    ESeconds = GSeconds - ?GREGORIAN_SECONDS_1970,
-    {ESeconds div 1000000, ESeconds rem 1000000, 0}.
-
+    case parse(Date) of
+	{DateS, {H, M, S, Ms} } ->
+	    GSeconds = calendar:datetime_to_gregorian_seconds({DateS, {H, M, S} }),
+	    ESeconds = GSeconds - ?GREGORIAN_SECONDS_1970,
+	    {ESeconds div 1000000, ESeconds rem 1000000, Ms};
+	DateTime ->
+	    GSeconds = calendar:datetime_to_gregorian_seconds(DateTime),
+	    ESeconds = GSeconds - ?GREGORIAN_SECONDS_1970,
+	    {ESeconds div 1000000, ESeconds rem 1000000, 0}
+    end.
 
 %%
 %% LOCAL FUNCTIONS
 %%
 
+
+%% Date/Times 22 Aug 2008 6:35.0001 PM
+parse([Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms | PAM], _Now, _Opts)
+  when ?is_meridian(PAM) andalso
+       (?is_us_sep(X) orelse ?is_world_sep(X))
+       andalso Year > 31 ->
+    {{Year, Month, Day}, {hour(Hour, PAM), Min, Sec}, {Ms}};
+parse([Month,X,Day,X,Year,Hour,$:,Min,$:,Sec,$., Ms | PAM], _Now, _Opts)
+  when ?is_meridian(PAM) andalso ?is_us_sep(X) ->
+    {{Year, Month, Day}, {hour(Hour, PAM), Min, Sec}, {Ms}};
+parse([Day,X,Month,X,Year,Hour,$:,Min,$:,Sec,$., Ms | PAM], _Now, _Opts)
+  when ?is_meridian(PAM) andalso ?is_world_sep(X) ->
+    {{Year, Month, Day}, {hour(Hour, PAM), Min, Sec}, {Ms}};
+
+parse([Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms], _Now, _Opts)
+  when  (?is_us_sep(X) orelse ?is_world_sep(X))
+       andalso Year > 31 ->
+    {{Year, Month, Day}, {hour(Hour,[]), Min, Sec}, {Ms}};
+parse([Month,X,Day,X,Year,Hour,$:,Min,$:,Sec,$., Ms], _Now, _Opts)
+  when ?is_us_sep(X) ->
+    {{Year, Month, Day}, {hour(Hour, []), Min, Sec}, {Ms}};
+parse([Day,X,Month,X,Year,Hour,$:,Min,$:,Sec,$., Ms ], _Now, _Opts)
+  when ?is_world_sep(X) ->
+    {{Year, Month, Day}, {hour(Hour, []), Min, Sec}, {Ms}};
+
 %% Times - 21:45, 13:45:54, 13:15PM etc
 parse([Hour,$:,Min,$:,Sec | PAM], {Date, _Time}, _O) when ?is_meridian(PAM) ->
     {Date, {hour(Hour, PAM), Min, Sec}};
@@ -138,7 +181,8 @@ parse([Month,X,Day,X,Year,Hour | PAM], _Date, _Opts)
   when ?is_meridian(PAM) andalso ?is_us_sep(X) ->
         {{Year, Month, Day}, {hour(Hour, PAM), 0, 0}};
 
-%% Time is "6:35 PM"
+
+%% Time is "6:35 PM" ms return
 parse([Year,X,Month,X,Day,Hour,$:,Min | PAM], _Date, _Opts)
   when ?is_meridian(PAM) andalso
        (?is_us_sep(X) orelse ?is_world_sep(X))
@@ -164,7 +208,6 @@ parse([Day,X,Month,X,Year,Hour,$:,Min,$:,Sec | PAM], _Now, _Opts)
   when ?is_meridian(PAM) andalso ?is_world_sep(X) ->
     {{Year, Month, Day}, {hour(Hour, PAM), Min, Sec}};
 
-
 parse([Day,Month,Year,Hour | PAM], _Now, _Opts)
   when ?is_meridian(PAM) ->
     {{Year, Month, Day}, {hour(Hour, PAM), 0, 0}};
@@ -181,9 +224,18 @@ parse(_Tokens, _Now, _Opts) ->
 tokenise([], Acc) ->
     lists:reverse(Acc);
 
+tokenise([N1, N2, N3, N4, N5, N6 | Rest], Acc)
+  when ?is_num(N1), ?is_num(N2), ?is_num(N3), ?is_num(N4), ?is_num(N5), ?is_num(N6) ->
+    tokenise(Rest, [ ltoi([N1, N2, N3, N4, N5, N6]) | Acc]);
+tokenise([N1, N2, N3, N4, N5 | Rest], Acc)
+  when ?is_num(N1), ?is_num(N2), ?is_num(N3), ?is_num(N4), ?is_num(N5) ->
+    tokenise(Rest, [ ltoi([N1, N2, N3, N4, N5]) | Acc]);
 tokenise([N1, N2, N3, N4 | Rest], Acc)
   when ?is_num(N1), ?is_num(N2), ?is_num(N3), ?is_num(N4) ->
     tokenise(Rest, [ ltoi([N1, N2, N3, N4]) | Acc]);
+tokenise([N1, N2, N3 | Rest], Acc)
+  when ?is_num(N1), ?is_num(N2), ?is_num(N3) ->
+    tokenise(Rest, [ ltoi([N1, N2, N3]) | Acc]);
 tokenise([N1, N2 | Rest], Acc)
   when ?is_num(N1), ?is_num(N2) ->
     tokenise(Rest, [ ltoi([N1, N2]) | Acc]);
@@ -264,6 +316,8 @@ tokenise("TH"++Rest, Acc) -> tokenise(Rest, Acc);
 tokenise("ND"++Rest, Acc) -> tokenise(Rest, Acc);
 tokenise("ST"++Rest, Acc) -> tokenise(Rest, Acc);
 tokenise("OF"++Rest, Acc) -> tokenise(Rest, Acc);
+tokenise("T"++Rest, Acc) -> tokenise(Rest, Acc);  % 2012-12-12T12:12:12 ISO formatting.
+tokenise([$. | Rest], Acc) -> tokenise(Rest, [$. | Acc]);  % 2012-12-12T12:12:12.xxxx ISO formatting.
 
 tokenise([Else | Rest], Acc) ->
     tokenise(Rest, [{bad_token, Else} | Acc]).
@@ -329,13 +383,13 @@ format([$z|T], {Date,_}=Dt, Acc) ->
     format(T, Dt, [itol(days_in_year(Date))|Acc]);
 
 %% Time Formats
-format([$a|T], {_,{H,_,_}}=Dt, Acc) when H > 12 ->
+format([$a|T], Dt={_,{H,_,_}}, Acc) when H > 12 ->
     format(T, Dt, ["pm"|Acc]);
-format([$a|T], Dt, Acc) ->
+format([$a|T], Dt={_,{_,_,_}}, Acc) ->
     format(T, Dt, ["am"|Acc]);
 format([$A|T], {_,{H,_,_}}=Dt, Acc) when H > 12 ->
     format(T, Dt, ["PM"|Acc]);
-format([$A|T], Dt, Acc) ->
+format([$A|T], Dt={_,{_,_,_}}, Acc) ->
     format(T, Dt, ["AM"|Acc]);
 format([$g|T], {_,{H,_,_}}=Dt, Acc) when H == 12; H == 0 ->
     format(T, Dt, ["12"|Acc]);
@@ -355,6 +409,38 @@ format([$i|T], {_,{_,M,_}}=Dt, Acc) ->
     format(T, Dt, [pad2(M)|Acc]);
 format([$s|T], {_,{_,_,S}}=Dt, Acc) ->
     format(T, Dt, [pad2(S)|Acc]);
+format([$f|T], {_,{_,_,_}}=Dt, Acc) ->
+    format(T, Dt, [itol(0)|Acc]);
+
+%% Time Formats ms
+format([$a|T], Dt={_,{H,_,_,_}}, Acc) when H > 12 ->
+    format(T, Dt, ["pm"|Acc]);
+format([$a|T], Dt={_,{_,_,_,_}}, Acc) ->
+    format(T, Dt, ["am"|Acc]);
+format([$A|T], {_,{H,_,_,_}}=Dt, Acc) when H > 12 ->
+    format(T, Dt, ["PM"|Acc]);
+format([$A|T], Dt={_,{_,_,_,_}}, Acc) ->
+    format(T, Dt, ["AM"|Acc]);
+format([$g|T], {_,{H,_,_,_}}=Dt, Acc) when H == 12; H == 0 ->
+    format(T, Dt, ["12"|Acc]);
+format([$g|T], {_,{H,_,_,_}}=Dt, Acc) when H > 12 ->
+    format(T, Dt, [itol(H-12)|Acc]);
+format([$g|T], {_,{H,_,_,_}}=Dt, Acc) ->
+    format(T, Dt, [itol(H)|Acc]);
+format([$G|T], {_,{H,_,_,_}}=Dt, Acc) ->
+    format(T, Dt, [itol(H)|Acc]);
+format([$h|T], {_,{H,_,_,_}}=Dt, Acc) when H > 12 ->
+    format(T, Dt, [pad2(H-12)|Acc]);
+format([$h|T], {_,{H,_,_,_}}=Dt, Acc) ->
+    format(T, Dt, [pad2(H)|Acc]);
+format([$H|T], {_,{H,_,_,_}}=Dt, Acc) ->
+    format(T, Dt, [pad2(H)|Acc]);
+format([$i|T], {_,{_,M,_,_}}=Dt, Acc) ->
+    format(T, Dt, [pad2(M)|Acc]);
+format([$s|T], {_,{_,_,S,_}}=Dt, Acc) ->
+    format(T, Dt, [pad2(S)|Acc]);
+format([$f|T], {_,{_,_,_,Ms}}=Dt, Acc) ->
+    format(T, Dt, [itol(Ms)|Acc]);
 
 %% Whole Dates
 format([$c|T], {{Y,M,D},{H,Min,S}}=Dt, Acc) ->
@@ -519,6 +605,7 @@ ltoi(X) ->
 -include_lib("eunit/include/eunit.hrl").
 
 -define(DATE, {{2001,3,10},{17,16,17}}).
+-define(DATEMS, {{2001,3,10},{17,16,17,123456}}).
 -define(ISO, "o \\WW").
 
 basic_format_test_() ->
@@ -674,3 +761,20 @@ iso_test_() ->
      ?_assertEqual("2009 W53",format(?ISO,{{2009,12,31},{1,1,1}})),
      ?_assertEqual("2009 W53",format(?ISO,{{2010,1,3}, {1,1,1}}))
     ].
+
+ms_test_() ->
+    Now=now(),
+    [
+     ?_assertEqual({{2012,12,12}, {12,12,12,1234}}, parse("2012-12-12T12:12:12.1234")),
+     ?_assertEqual(format("H:m:s.f \\m \\i\\s \\m\\o\\n\\t\\h",?DATEMS),
+                   "17:03:17.123456 m is month"),
+     ?_assertEqual(format("Y-m-d\\TH:i:s.f",?DATEMS),
+                   "2001-03-10T17:16:17.123456"),
+     ?_assertEqual(format("Y-m-d\\TH:i:s.f",nparse("2001-03-10T05:16:17.123456")),
+                   "2001-03-10T05:16:17.123456"),
+     ?_assertEqual(format("Y-m-d\\TH:i:s.f",nparse("2001-03-10T05:16:17.123456")),
+                   "2001-03-10T05:16:17.123456"),
+     ?_assertEqual(format("Y-m-d\\TH:i:s.f",nparse("2001-03-10T15:16:17.123456")),
+                   "2001-03-10T15:16:17.123456"),
+     ?_assertEqual(Now, nparse(format("Y-m-d\\TH:i:s.f", Now)))
+    ].
diff --git a/src/ec_dictionary.erl b/src/ec_dictionary.erl
index 1061665..416df72 100644
--- a/src/ec_dictionary.erl
+++ b/src/ec_dictionary.erl
@@ -41,6 +41,8 @@
 -type key(T) :: T.
 -type value(T) :: T.
 
+-ifdef(have_callback_support).
+
 -callback new() -> any().
 -callback has_key(key(any()), any()) -> boolean().
 -callback get(key(any()), any()) -> any().
@@ -52,6 +54,27 @@
 -callback from_list([{key(any()), value(any())}]) -> any().
 -callback keys(any()) -> [key(any())].
 
+-else.
+
+%% In the case where R14 or lower is being used to compile the system
+%% we need to export a behaviour info
+-export([behaviour_info/1]).
+-spec behaviour_info(atom()) -> [{atom(), arity()}] | undefined.
+behaviour_info(callbacks) ->
+    [{new, 0},
+     {has_key, 2},
+     {get, 2},
+     {add, 3},
+     {remove, 2},
+     {has_value, 2},
+     {size, 1},
+     {to_list, 1},
+     {from_list, 1},
+     {keys, 1}];
+behaviour_info(_Other) ->
+    undefined.
+-endif.
+
 %%%===================================================================
 %%% API
 %%%===================================================================
diff --git a/src/ec_semver.erl b/src/ec_semver.erl
index ac810e5..5855c23 100644
--- a/src/ec_semver.erl
+++ b/src/ec_semver.erl
@@ -1,4 +1,3 @@
-
 %%%-------------------------------------------------------------------
 %%% @copyright (C) 2011, Erlware LLC
 %%% @doc
@@ -211,14 +210,18 @@ internal_parse_version([MMP, AlphaPart, BuildPart, _]) ->
 %% @doc helper function for the peg grammer to parse the iolist into a major_minor_patch
 -spec parse_major_minor_patch_minpatch(iolist()) -> major_minor_patch_minpatch().
 parse_major_minor_patch_minpatch([MajVsn, [], [], []]) ->
-    MajVsn;
+    strip_maj_version(MajVsn);
 parse_major_minor_patch_minpatch([MajVsn, [<<".">>, MinVsn], [], []]) ->
-    {MajVsn, MinVsn};
-parse_major_minor_patch_minpatch([MajVsn, [<<".">>, MinVsn], [<<".">>, PatchVsn], []]) ->
-    {MajVsn, MinVsn, PatchVsn};
-parse_major_minor_patch_minpatch([MajVsn, [<<".">>, MinVsn],
-                         [<<".">>, PatchVsn], [<<".">>, MinPatch]]) ->
-    {MajVsn, MinVsn, PatchVsn, MinPatch}.
+    {strip_maj_version(MajVsn), MinVsn};
+parse_major_minor_patch_minpatch([MajVsn,
+                                  [<<".">>, MinVsn],
+                                  [<<".">>, PatchVsn], []]) ->
+    {strip_maj_version(MajVsn), MinVsn, PatchVsn};
+parse_major_minor_patch_minpatch([MajVsn,
+                                  [<<".">>, MinVsn],
+                                  [<<".">>, PatchVsn],
+                                  [<<".">>, MinPatch]]) ->
+    {strip_maj_version(MajVsn), MinVsn, PatchVsn, MinPatch}.
 
 %% @doc helper function for the peg grammer to parse the iolist into an alpha part
 -spec parse_alpha_part(iolist()) -> [alpha_part()].
@@ -245,6 +248,14 @@ format_alpha_part([<<".">>, AlphaPart]) ->
 %%%===================================================================
 %%% Internal Functions
 %%%===================================================================
+-spec strip_maj_version(iolist()) -> version_element().
+strip_maj_version([<<"v">>, MajVsn]) ->
+    MajVsn;
+strip_maj_version([[], MajVsn]) ->
+    MajVsn;
+strip_maj_version(MajVsn) ->
+    MajVsn.
+
 -spec to_list(integer() | binary() | string()) -> string() | binary().
 to_list(Detail) when erlang:is_integer(Detail) ->
     erlang:integer_to_list(Detail);
@@ -308,8 +319,12 @@ internal_pes(Vsn, LVsn) ->
 eql_test() ->
     ?assertMatch(true, eql("1.0.0-alpha",
                            "1.0.0-alpha")),
+    ?assertMatch(true, eql("v1.0.0-alpha",
+                           "1.0.0-alpha")),
     ?assertMatch(true, eql("1",
                            "1.0.0")),
+    ?assertMatch(true, eql("v1",
+                           "v1.0.0")),
     ?assertMatch(true, eql("1.0",
                            "1.0.0")),
     ?assertMatch(true, eql("1.0.0",
@@ -322,6 +337,8 @@ eql_test() ->
                            "1.0.0-alpha.1+build.1")),
     ?assertMatch(true, eql("1.0-alpha.1+build.1",
                            "1.0.0.0-alpha.1+build.1")),
+    ?assertMatch(true, eql("1.0-alpha.1+build.1",
+                           "v1.0.0.0-alpha.1+build.1")),
     ?assertMatch(true, eql("aa", "aa")),
     ?assertMatch(true, eql("AA.BB", "AA.BB")),
     ?assertMatch(true, eql("BBB-super", "BBB-super")),
diff --git a/src/ec_semver_parser.peg b/src/ec_semver_parser.peg
index 09779ae..1210ff9 100644
--- a/src/ec_semver_parser.peg
+++ b/src/ec_semver_parser.peg
@@ -1,7 +1,7 @@
 semver <- major_minor_patch_min_patch ("-" alpha_part ("." alpha_part)*)? ("+" alpha_part ("." alpha_part)*)?  !.
        ` ec_semver:internal_parse_version(Node) ` ;
 
-major_minor_patch_min_patch <- version_part ("." version_part)? ("." version_part)? ("." version_part)? ;
+major_minor_patch_min_patch <- ("v"? numeric_part / alpha_part)  ("." version_part)? ("." version_part)? ("." version_part)? ;
 
 version_part <- numeric_part / alpha_part ;