diff --git a/example/test.lua b/example/test.lua
index 6a7bf87..aef72cd 100644
--- a/example/test.lua
+++ b/example/test.lua
@@ -1,4 +1,4 @@
-require 'person_pb'
+person_pb = require 'person_pb'
 
 local person = person_pb.Person()
 person.id = 1000
diff --git a/protobuf/containers.lua b/protobuf/containers.lua
index 3f9f878..893dc1f 100644
--- a/protobuf/containers.lua
+++ b/protobuf/containers.lua
@@ -21,7 +21,7 @@ local table = table
 local rawset = rawset
 local error = error
 
-module "protobuf.containers"
+local containers = {}
 
 local _RCFC_meta = {
   add = function(self)
@@ -47,7 +47,7 @@ local _RCFC_meta = {
 }
 _RCFC_meta.__index = _RCFC_meta
 
-function RepeatedCompositeFieldContainer(listener, message_descriptor)
+function containers.RepeatedCompositeFieldContainer(listener, message_descriptor)
   local o = {
     _listener = listener,
     _message_descriptor = message_descriptor
@@ -71,9 +71,11 @@ local _RSFC_meta = {
 }
 _RSFC_meta.__index = _RSFC_meta
 
-function RepeatedScalarFieldContainer(listener, type_checker)
+function containers.RepeatedScalarFieldContainer(listener, type_checker)
   local o = {}
   o._listener = listener
   o._type_checker = type_checker
   return setmetatable(o, _RSFC_meta)
 end
+
+return containers
diff --git a/protobuf/decoder.lua b/protobuf/decoder.lua
index f927830..aabef69 100644
--- a/protobuf/decoder.lua
+++ b/protobuf/decoder.lua
@@ -27,7 +27,7 @@ local pb = require "protobuf.pb"
 local encoder = require "protobuf.encoder"
 local wire_format = require "protobuf.wire_format"
 
-module "protobuf.decoder"
+local decoder = {}
 
 local _DecodeVarint = pb.varint_decoder
 local _DecodeSignedVarint = pb.signed_varint_decoder
@@ -35,7 +35,7 @@ local _DecodeSignedVarint = pb.signed_varint_decoder
 local _DecodeVarint32 = pb.varint_decoder
 local _DecodeSignedVarint32 = pb.signed_varint_decoder
 
-ReadTag = pb.read_tag
+decoder.ReadTag = pb.read_tag
 
 local function _SimpleDecoder(wire_type, decode_value)
   return function(field_number, is_repeated, is_packed, key, new_default)
@@ -110,7 +110,7 @@ end
 local function _StructPackDecoder(wire_type, value_size, format)
   local struct_unpack = pb.struct_unpack
 
-  function InnerDecode(buffer, pos)
+  local function InnerDecode(buffer, pos)
     local new_pos = pos + value_size
     local result = struct_unpack(format, buffer, pos)
     return result, new_pos
@@ -122,27 +122,27 @@ local function _Boolean(value)
   return value ~= 0
 end
 
-Int32Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeSignedVarint32)
-EnumDecoder = Int32Decoder
+decoder.Int32Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeSignedVarint32)
+decoder.EnumDecoder = decoder.Int32Decoder
 
-Int64Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeSignedVarint)
+decoder.Int64Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeSignedVarint)
 
-UInt32Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint32)
-UInt64Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint)
+decoder.UInt32Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint32)
+decoder.UInt64Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint)
 
-SInt32Decoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint32, wire_format.ZigZagDecode32)
-SInt64Decoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint, wire_format.ZigZagDecode64)
+decoder.SInt32Decoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint32, wire_format.ZigZagDecode32)
+decoder.SInt64Decoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint, wire_format.ZigZagDecode64)
 
-Fixed32Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('I'))
-Fixed64Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('Q'))
-SFixed32Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('i'))
-SFixed64Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('q'))
-FloatDecoder    = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('f'))
-DoubleDecoder   = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('d'))
+decoder.Fixed32Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('I'))
+decoder.Fixed64Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('Q'))
+decoder.SFixed32Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('i'))
+decoder.SFixed64Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('q'))
+decoder.FloatDecoder    = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('f'))
+decoder.DoubleDecoder   = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('d'))
 
-BoolDecoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint, _Boolean)
+decoder.BoolDecoder = _ModifiedDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint, _Boolean)
 
-function StringDecoder(field_number, is_repeated, is_packed, key, new_default)
+function decoder.StringDecoder(field_number, is_repeated, is_packed, key, new_default)
   local DecodeVarint = _DecodeVarint
   local sub = string.sub
   --local unicode = unicode
@@ -184,7 +184,7 @@ function StringDecoder(field_number, is_repeated, is_packed, key, new_default)
   end
 end
 
-function BytesDecoder(field_number, is_repeated, is_packed, key, new_default)
+function decoder.BytesDecoder(field_number, is_repeated, is_packed, key, new_default)
   local DecodeVarint = _DecodeVarint
   local sub = string.sub
   assert(not is_packed)
@@ -225,7 +225,7 @@ function BytesDecoder(field_number, is_repeated, is_packed, key, new_default)
   end
 end
 
-function MessageDecoder(field_number, is_repeated, is_packed, key, new_default)
+function decoder.MessageDecoder(field_number, is_repeated, is_packed, key, new_default)
   local DecodeVarint = _DecodeVarint
   local sub = string.sub
   assert(not is_packed)
@@ -275,13 +275,13 @@ function MessageDecoder(field_number, is_repeated, is_packed, key, new_default)
   end
 end
 
-function _SkipVarint(buffer, pos, pend)
+local function _SkipVarint(buffer, pos, pend)
   local value
   value, pos = _DecodeVarint(buffer, pos)
   return pos
 end
 
-function _SkipFixed64(buffer, pos, pend)
+local function _SkipFixed64(buffer, pos, pend)
   pos = pos + 8
   if pos > pend then
     error('Truncated message.')
@@ -289,7 +289,7 @@ function _SkipFixed64(buffer, pos, pend)
   return pos
 end
 
-function _SkipLengthDelimited(buffer, pos, pend)
+local function _SkipLengthDelimited(buffer, pos, pend)
   local size
   size, pos = _DecodeVarint(buffer, pos)
   pos = pos + size
@@ -299,7 +299,7 @@ function _SkipLengthDelimited(buffer, pos, pend)
   return pos
 end
 
-function _SkipFixed32(buffer, pos, pend)
+local function _SkipFixed32(buffer, pos, pend)
   pos = pos + 4
   if pos > pend then
     error('Truncated message.')
@@ -307,17 +307,21 @@ function _SkipFixed32(buffer, pos, pend)
   return pos
 end
 
-function _RaiseInvalidWireType(buffer, pos, pend)
+local function _Unsupported(buffer, pos, pend)
+  error('Field not supported.')
+end
+
+local function _RaiseInvalidWireType(buffer, pos, pend)
   error('Tag had invalid wire type.')
 end
 
-function _FieldSkipper()
-  WIRETYPE_TO_SKIPPER = {
+local function _FieldSkipper()
+  local WIRETYPE_TO_SKIPPER = {
     _SkipVarint,
     _SkipFixed64,
     _SkipLengthDelimited,
-    _SkipGroup,
-    _EndGroup,
+    _Unsupported, --_SkipGroup,
+    _Unsupported, --_EndGroup,
     _SkipFixed32,
     _RaiseInvalidWireType,
     _RaiseInvalidWireType,
@@ -333,4 +337,6 @@ function _FieldSkipper()
   end
 end
 
-SkipField = _FieldSkipper()
+decoder.SkipField = _FieldSkipper()
+
+return decoder
\ No newline at end of file
diff --git a/protobuf/descriptor.lua b/protobuf/descriptor.lua
index c11da5d..38d1dc1 100644
--- a/protobuf/descriptor.lua
+++ b/protobuf/descriptor.lua
@@ -16,9 +16,9 @@
 --------------------------------------------------------------------------------
 --
 
-module "protobuf.descriptor"
+local descriptor = {}
 
-FieldDescriptor = {
+descriptor.FieldDescriptor = {
   TYPE_DOUBLE         = 1,
   TYPE_FLOAT          = 2,
   TYPE_INT64          = 3,
@@ -58,3 +58,5 @@ FieldDescriptor = {
   LABEL_REPEATED      = 3,
   MAX_LABEL           = 3
 }
+
+return descriptor
\ No newline at end of file
diff --git a/protobuf/encoder.lua b/protobuf/encoder.lua
index f013f4f..cdc5064 100644
--- a/protobuf/encoder.lua
+++ b/protobuf/encoder.lua
@@ -24,9 +24,9 @@ local assert = assert
 local pb = require "protobuf.pb"
 local wire_format = require "protobuf.wire_format"
 
-module "protobuf.encoder"
+local encoder = {}
 
-function _VarintSize(value)
+local function _VarintSize(value)
   if value <= 0x7f then return 1 end
   if value <= 0x3fff then return 2 end
   if value <= 0x1fffff then return 3 end
@@ -34,7 +34,7 @@ function _VarintSize(value)
   return 5
 end
 
-function _SignedVarintSize(value)
+local function _SignedVarintSize(value)
   if value < 0 then return 10 end
   if value <= 0x7f then return 1 end
   if value <= 0x3fff then return 2 end
@@ -43,11 +43,11 @@ function _SignedVarintSize(value)
   return 5
 end
 
-function _TagSize(field_number)
+local function _TagSize(field_number)
   return _VarintSize(wire_format.PackTag(field_number, 0))
 end
 
-function _SimpleSizer(compute_value_size)
+local function _SimpleSizer(compute_value_size)
   return function(field_number, is_repeated, is_packed)
     local tag_size = _TagSize(field_number)
     if is_packed then
@@ -75,7 +75,7 @@ function _SimpleSizer(compute_value_size)
   end
 end
 
-function _ModifiedSizer(compute_value_size, modify_value)
+local function _ModifiedSizer(compute_value_size, modify_value)
   return function (field_number, is_repeated, is_packed)
     local tag_size = _TagSize(field_number)
     if is_packed then
@@ -103,7 +103,7 @@ function _ModifiedSizer(compute_value_size, modify_value)
   end
 end
 
-function _FixedSizer(value_size)
+local function _FixedSizer(value_size)
   return function (field_number, is_repeated, is_packed)
     local tag_size = _TagSize(field_number)
     if is_packed then
@@ -126,27 +126,27 @@ function _FixedSizer(value_size)
   end
 end
 
-Int32Sizer = _SimpleSizer(_SignedVarintSize)
-Int64Sizer = Int32Sizer
-EnumSizer = Int32Sizer
+encoder.Int32Sizer = _SimpleSizer(_SignedVarintSize)
+encoder.Int64Sizer = encoder.Int32Sizer
+encoder.EnumSizer = encoder.Int32Sizer
 
-UInt32Sizer = _SimpleSizer(_VarintSize)
-UInt64Sizer = UInt32Sizer
+encoder.UInt32Sizer = _SimpleSizer(_VarintSize)
+encoder.UInt64Sizer = encoder.UInt32Sizer
 
-SInt32Sizer = _ModifiedSizer(_SignedVarintSize, wire_format.ZigZagEncode)
-SInt64Sizer = SInt32Sizer
+encoder.SInt32Sizer = _ModifiedSizer(_SignedVarintSize, wire_format.ZigZagEncode)
+encoder.SInt64Sizer = encoder.SInt32Sizer
 
-Fixed32Sizer = _FixedSizer(4)
-SFixed32Sizer = Fixed32Sizer
-FloatSizer = Fixed32Sizer
+encoder.Fixed32Sizer = _FixedSizer(4)
+encoder.SFixed32Sizer = encoder.Fixed32Sizer
+encoder.FloatSizer = encoder.Fixed32Sizer
 
-Fixed64Sizer = _FixedSizer(8)
-SFixed64Sizer = Fixed64Sizer
-DoubleSizer = Fixed64Sizer
+encoder.Fixed64Sizer = _FixedSizer(8)
+encoder.SFixed64Sizer = encoder.Fixed64Sizer
+encoder.DoubleSizer = encoder.Fixed64Sizer
 
-BoolSizer = _FixedSizer(1)
+encoder.BoolSizer = _FixedSizer(1)
 
-function StringSizer(field_number, is_repeated, is_packed)
+function encoder.StringSizer(field_number, is_repeated, is_packed)
   local tag_size = _TagSize(field_number)
   local VarintSize = _VarintSize
   assert(not is_packed)
@@ -167,7 +167,7 @@ function StringSizer(field_number, is_repeated, is_packed)
   end
 end
 
-function BytesSizer(field_number, is_repeated, is_packed)
+function encoder.BytesSizer(field_number, is_repeated, is_packed)
   local tag_size = _TagSize(field_number)
   local VarintSize = _VarintSize
   assert(not is_packed)
@@ -188,7 +188,7 @@ function BytesSizer(field_number, is_repeated, is_packed)
   end
 end
 
-function MessageSizer(field_number, is_repeated, is_packed)
+function encoder.MessageSizer(field_number, is_repeated, is_packed)
   local tag_size = _TagSize(field_number)
   local VarintSize = _VarintSize
   assert(not is_packed)
@@ -212,23 +212,23 @@ end
 local _EncodeVarint = pb.varint_encoder
 local _EncodeSignedVarint = pb.signed_varint_encoder
 
-function _VarintBytes(value)
+local function _VarintBytes(value)
   local out = {}
-  local write = function(value)
-    out[#out + 1 ] = value
+  local write = function(v)
+    out[#out + 1 ] = v
   end
   _EncodeSignedVarint(write, value)
   return table.concat(out)
 end
 
-function TagBytes(field_number, wire_type)
+function encoder.TagBytes(field_number, wire_type)
   return _VarintBytes(wire_format.PackTag(field_number, wire_type))
 end
 
-function _SimpleEncoder(wire_type, encode_value, compute_value_size)
+local function _SimpleEncoder(wire_type, encode_value, compute_value_size)
   return function(field_number, is_repeated, is_packed)
     if is_packed then
-      local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+      local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
       local EncodeVarint = _EncodeVarint
       return function(write, value)
         write(tag_bytes)
@@ -242,7 +242,7 @@ function _SimpleEncoder(wire_type, encode_value, compute_value_size)
         end
       end
     elseif is_repeated then
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function(write, value)
         for _, element in ipairs(value) do
           write(tag_bytes)
@@ -250,7 +250,7 @@ function _SimpleEncoder(wire_type, encode_value, compute_value_size)
         end
       end
     else
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function(write, value)
         write(tag_bytes)
         encode_value(write, value)
@@ -259,10 +259,10 @@ function _SimpleEncoder(wire_type, encode_value, compute_value_size)
   end
 end
 
-function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_value)
+local function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_value)
   return function (field_number, is_repeated, is_packed)
     if is_packed then
-      local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+      local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
       local EncodeVarint = _EncodeVarint
       return function (write, value)
         write(tag_bytes)
@@ -276,7 +276,7 @@ function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_va
         end
       end
     elseif is_repeated then
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function (write, value)
         for _, element in ipairs(value) do
           write(tag_bytes)
@@ -284,7 +284,7 @@ function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_va
         end
       end
     else
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function (write, value)
         write(tag_bytes)
         encode_value(write, modify_value(value))
@@ -293,11 +293,11 @@ function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_va
   end
 end
 
-function _StructPackEncoder(wire_type, value_size, format)
+local function _StructPackEncoder(wire_type, value_size, format)
   return function(field_number, is_repeated, is_packed)
     local struct_pack = pb.struct_pack
     if is_packed then
-      local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+      local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
       local EncodeVarint = _EncodeVarint
       return function (write, value)
         write(tag_bytes)
@@ -307,7 +307,7 @@ function _StructPackEncoder(wire_type, value_size, format)
         end
       end
     elseif is_repeated then
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function (write, value)
         for _, element in ipairs(value) do
           write(tag_bytes)
@@ -315,7 +315,7 @@ function _StructPackEncoder(wire_type, value_size, format)
         end
       end
     else
-      local tag_bytes = TagBytes(field_number, wire_type)
+      local tag_bytes = encoder.TagBytes(field_number, wire_type)
       return function (write, value)
         write(tag_bytes)
         struct_pack(write, format, value)
@@ -324,35 +324,35 @@ function _StructPackEncoder(wire_type, value_size, format)
   end
 end
 
-Int32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeSignedVarint, _SignedVarintSize)
-Int64Encoder = Int32Encoder
-EnumEncoder = Int32Encoder
+encoder.Int32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeSignedVarint, _SignedVarintSize)
+encoder.Int64Encoder = encoder.Int32Encoder
+encoder.EnumEncoder = encoder.Int32Encoder
 
-UInt32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize)
-UInt64Encoder = UInt32Encoder
+encoder.UInt32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize)
+encoder.UInt64Encoder = encoder.UInt32Encoder
 
-SInt32Encoder = _ModifiedEncoder(
+encoder.SInt32Encoder = _ModifiedEncoder(
   wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize,
   wire_format.ZigZagEncode32
 )
 
-SInt64Encoder = _ModifiedEncoder(
+encoder.SInt64Encoder = _ModifiedEncoder(
   wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize,
   wire_format.ZigZagEncode64
 )
 
-Fixed32Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('I'))
-Fixed64Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('Q'))
-SFixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('i'))
-SFixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('q'))
-FloatEncoder    = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('f'))
-DoubleEncoder   = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('d'))
+encoder.Fixed32Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('I'))
+encoder.Fixed64Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('Q'))
+encoder.SFixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('i'))
+encoder.SFixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('q'))
+encoder.FloatEncoder    = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('f'))
+encoder.DoubleEncoder   = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('d'))
 
-function BoolEncoder(field_number, is_repeated, is_packed)
+function encoder.BoolEncoder(field_number, is_repeated, is_packed)
   local false_byte = '\0'
   local true_byte = '\1'
   if is_packed then
-    local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+    local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
     local EncodeVarint = _EncodeVarint
     return function (write, value)
       write(tag_bytes)
@@ -366,7 +366,7 @@ function BoolEncoder(field_number, is_repeated, is_packed)
       end
     end
   elseif is_repeated then
-    local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT)
+    local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_VARINT)
     return function(write, value)
       for _, element in ipairs(value) do
         write(tag_bytes)
@@ -378,7 +378,7 @@ function BoolEncoder(field_number, is_repeated, is_packed)
       end
     end
   else
-    local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT)
+    local tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_VARINT)
     return function (write, value)
       write(tag_bytes)
       if value then
@@ -389,8 +389,8 @@ function BoolEncoder(field_number, is_repeated, is_packed)
   end
 end
 
-function StringEncoder(field_number, is_repeated, is_packed)
-  local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+function encoder.StringEncoder(field_number, is_repeated, is_packed)
+  local tag = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
   local EncodeVarint = _EncodeVarint
   assert(not is_packed)
   if is_repeated then
@@ -412,8 +412,8 @@ function StringEncoder(field_number, is_repeated, is_packed)
   end
 end
 
-function BytesEncoder(field_number, is_repeated, is_packed)
-  local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+function encoder.BytesEncoder(field_number, is_repeated, is_packed)
+  local tag = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
   local EncodeVarint = _EncodeVarint
   assert(not is_packed)
   if is_repeated then
@@ -433,8 +433,8 @@ function BytesEncoder(field_number, is_repeated, is_packed)
   end
 end
 
-function MessageEncoder(field_number, is_repeated, is_packed)
-  local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+function encoder.MessageEncoder(field_number, is_repeated, is_packed)
+  local tag = encoder.TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
   local EncodeVarint = _EncodeVarint
   assert(not is_packed)
   if is_repeated then
@@ -453,3 +453,5 @@ function MessageEncoder(field_number, is_repeated, is_packed)
     end
   end
 end
+
+return encoder
\ No newline at end of file
diff --git a/protobuf/init.lua b/protobuf/init.lua
index f7d6fb3..263a618 100644
--- a/protobuf/init.lua
+++ b/protobuf/init.lua
@@ -35,11 +35,11 @@ local encoder = require "protobuf.encoder"
 local decoder = require "protobuf.decoder"
 local listener_mod = require "protobuf.listener"
 local containers = require "protobuf.containers"
-local descriptor = require "protobuf.descriptor"
-local FieldDescriptor = descriptor.FieldDescriptor
+local pb_descriptor = require "protobuf.descriptor"
+local FieldDescriptor = pb_descriptor.FieldDescriptor
 local text_format = require "protobuf.text_format"
 
-module "protobuf"
+local protobuf = {}
 
 local function make_descriptor(name, descriptor, usable_key)
   local meta = {
@@ -56,7 +56,7 @@ local function make_descriptor(name, descriptor, usable_key)
     return setmetatable({}, meta)
   end
 
-  _M[name] = setmetatable(descriptor, meta);
+  protobuf[name] = setmetatable(descriptor, meta);
 end
 
 make_descriptor("Descriptor", {}, {
@@ -231,27 +231,6 @@ local TYPE_TO_DECODER = {
   [FieldDescriptor.TYPE_SINT64] = decoder.SInt64Decoder
 }
 
-local FIELD_TYPE_TO_WIRE_TYPE = {
-  [FieldDescriptor.TYPE_DOUBLE] = wire_format.WIRETYPE_FIXED64,
-  [FieldDescriptor.TYPE_FLOAT] = wire_format.WIRETYPE_FIXED32,
-  [FieldDescriptor.TYPE_INT64] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_UINT64] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_INT32] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_FIXED64] = wire_format.WIRETYPE_FIXED64,
-  [FieldDescriptor.TYPE_FIXED32] = wire_format.WIRETYPE_FIXED32,
-  [FieldDescriptor.TYPE_BOOL] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_STRING] = wire_format.WIRETYPE_LENGTH_DELIMITED,
-  [FieldDescriptor.TYPE_GROUP] = wire_format.WIRETYPE_START_GROUP,
-  [FieldDescriptor.TYPE_MESSAGE] = wire_format.WIRETYPE_LENGTH_DELIMITED,
-  [FieldDescriptor.TYPE_BYTES] = wire_format.WIRETYPE_LENGTH_DELIMITED,
-  [FieldDescriptor.TYPE_UINT32] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_ENUM] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_SFIXED32] = wire_format.WIRETYPE_FIXED32,
-  [FieldDescriptor.TYPE_SFIXED64] = wire_format.WIRETYPE_FIXED64,
-  [FieldDescriptor.TYPE_SINT32] = wire_format.WIRETYPE_VARINT,
-  [FieldDescriptor.TYPE_SINT64] = wire_format.WIRETYPE_VARINT
-}
-
 local function IsTypePackable(field_type)
   return NON_PACKABLE_TYPES[field_type] == nil
 end
@@ -283,7 +262,7 @@ local function _DefaultValueConstructorForField(field)
   if field.cpp_type == FieldDescriptor.CPPTYPE_MESSAGE then
     local message_type = field.message_type
     return function (message)
-      result = message_type._concrete_class()
+      local result = message_type._concrete_class()
       result._SetListener(message._listener_for_children)
       return result
     end
@@ -297,18 +276,25 @@ local function _AttachFieldHelpers(message_meta, field_descriptor)
   local is_repeated = (field_descriptor.label == FieldDescriptor.LABEL_REPEATED)
   local is_packed = (field_descriptor.has_options and field_descriptor.GetOptions().packed)
 
-  rawset(field_descriptor, "_encoder", TYPE_TO_ENCODER[field_descriptor.type](field_descriptor.number, is_repeated, is_packed))
-  rawset(field_descriptor, "_sizer", TYPE_TO_SIZER[field_descriptor.type](field_descriptor.number, is_repeated, is_packed))
+  rawset(field_descriptor, "_encoder",
+    TYPE_TO_ENCODER[field_descriptor.type](field_descriptor.number, is_repeated, is_packed))
+  rawset(field_descriptor, "_sizer",
+    TYPE_TO_SIZER[field_descriptor.type](field_descriptor.number, is_repeated, is_packed))
   rawset(field_descriptor, "_default_constructor", _DefaultValueConstructorForField(field_descriptor))
 
-  local AddDecoder = function(wiretype, is_packed)
+  local AddDecoder = function(wiretype, _is_packed)
     local tag_bytes = encoder.TagBytes(field_descriptor.number, wiretype)
-    message_meta._decoders_by_tag[tag_bytes] = TYPE_TO_DECODER[field_descriptor.type](field_descriptor.number, is_repeated, is_packed, field_descriptor, field_descriptor._default_constructor)
+    message_meta._decoders_by_tag[tag_bytes] =
+    TYPE_TO_DECODER[field_descriptor.type](field_descriptor.number,
+                                           is_repeated,
+                                           _is_packed,
+                                           field_descriptor,
+                                           field_descriptor._default_constructor)
   end
 
-  AddDecoder(FIELD_TYPE_TO_WIRE_TYPE[field_descriptor.type], False)
+  AddDecoder(FIELD_TYPE_TO_WIRE_TYPE[field_descriptor.type], false)
   if is_repeated and IsTypePackable(field_descriptor.type) then
-    AddDecoder(wire_format.WIRETYPE_LENGTH_DELIMITED, True)
+    AddDecoder(wire_format.WIRETYPE_LENGTH_DELIMITED, true)
   end
 end
 
@@ -391,7 +377,7 @@ local function _AddPropertiesForNonRepeatedScalarField(field, message)
 end
 
 local function _AddPropertiesForField(field, message_meta)
-  constant_name = field.name:upper() .. "_FIELD_NUMBER"
+  local constant_name = field.name:upper() .. "_FIELD_NUMBER"
   message_meta._member[constant_name] = field.number
 
   if field.label == FieldDescriptor.LABEL_REPEATED then
@@ -426,7 +412,8 @@ local _ED_meta = {
     local _extended_message = rawget(self, "_extended_message")
     if (extension_handle.label == FieldDescriptor.LABEL_REPEATED or
         extension_handle.cpp_type == FieldDescriptor.CPPTYPE_MESSAGE) then
-      error('Cannot assign to extension "'.. extension_handle.full_name .. '" because it is a repeated or composite type.')
+      error('Cannot assign to extension "'.. extension_handle.full_name ..
+            '" because it is a repeated or composite type.')
     end
     local type_checker = GetTypeChecker(extension_handle.cpp_type, extension_handle.type)
     type_checker.CheckValue(value)
@@ -493,18 +480,18 @@ end
 local function _AddListFieldsMethod(message_descriptor, message_meta)
   message_meta._member.ListFields = function (self)
     local list_field = function(fields)
-      local f, s, v = pairs(self._fields)
-      local iter = function(a, i)
+      local s, v
+      local iter = function()
         while true do
-          local descriptor, value = f(a, i)
-          if descriptor == nil then
+          s, v = next(fields, s)
+          if s == nil then
             return
-          elseif _IsPresent(descriptor, value) then
-            return descriptor, value
+          elseif _IsPresent(s, v) then
+            return s, v
           end
         end
       end
-      return iter, s, v
+      return iter
     end
     return list_field(self._fields)
   end
@@ -518,12 +505,12 @@ local function _AddHasFieldMethod(message_descriptor, message_meta)
     end
   end
   message_meta._member.HasField = function (self, field_name)
-    field = singular_fields[field_name]
+    local field = singular_fields[field_name]
     if field == nil then
       error('Protocol message has no singular "'.. field_name.. '" field.')
     end
     if field.cpp_type == FieldDescriptor.CPPTYPE_MESSAGE then
-      value = self._fields[field]
+      local value = self._fields[field]
       return value ~= nil  and value._is_present_in_parent
     else
       return self._fields[field]
@@ -573,7 +560,7 @@ local function _AddHasExtensionMethod(message_meta)
       error(extension_handle.full_name .. ' is repeated.')
     end
     if extension_handle.cpp_type == FieldDescriptor.CPPTYPE_MESSAGE then
-      value = self._fields[extension_handle]
+      local value = self._fields[extension_handle]
       return value ~= nil and value._is_present_in_parent
     else
       return self._fields[extension_handle]
@@ -749,6 +736,7 @@ local function _AddIsInitializedMethod(message_descriptor, message_meta)
 
     for field, value in message_meta._member.ListFields(self) do
       if field.cpp_type == FieldDescriptor.CPPTYPE_MESSAGE then
+        local name
         if field.is_extension then
           name = string.format("(%s)", field.full_name)
         else
@@ -756,15 +744,15 @@ local function _AddIsInitializedMethod(message_descriptor, message_meta)
         end
         if field.label == FieldDescriptor.LABEL_REPEATED then
           for i, element in ipairs(value) do
-            prefix = string.format("%s[%d].", name, i)
-            sub_errors = element:FindInitializationErrors()
+            local prefix = string.format("%s[%d].", name, i)
+            local sub_errors = element:FindInitializationErrors()
             for _, e in ipairs(sub_errors) do
               errors[#errors + 1] = prefix .. e
             end
           end
         else
-          prefix = name .. "."
-          sub_errors = value:FindInitializationErrors()
+          local prefix = name .. "."
+          local sub_errors = value:FindInitializationErrors()
           for _, e in ipairs(sub_errors) do
             errors[#errors + 1] = prefix .. e
           end
@@ -784,6 +772,7 @@ local function _AddMergeFromMethod(message_meta)
     message_meta._member._Modified(self)
 
     local fields = self._fields
+    local field_value
 
     for field, value in pairs(msg._fields) do
       if field.label == LABEL_REPEATED or field.cpp_type == CPPTYPE_MESSAGE then
@@ -860,7 +849,7 @@ local function property_setter(message_meta)
 	end
 end
 
-function _AddClassAttributesForNestedExtensions(descriptor, message_meta)
+local function _AddClassAttributesForNestedExtensions(descriptor, message_meta)
   local extension_dict = descriptor._extensions_by_name
   for extension_name, extension_field in pairs(extension_dict) do
     message_meta._member[extension_name] = extension_field
@@ -894,7 +883,7 @@ local function Message(descriptor)
 
   if rawget(descriptor, "_concrete_class") == nil then
     rawset(descriptor, "_concrete_class", ns)
-    for k, field in ipairs(descriptor.fields) do
+    for _, field in ipairs(descriptor.fields) do
       _AttachFieldHelpers(message_meta, field)
     end
   end
@@ -912,4 +901,6 @@ local function Message(descriptor)
   return ns
 end
 
-_M.Message = Message
+protobuf.Message = Message
+
+return protobuf
diff --git a/protobuf/listener.lua b/protobuf/listener.lua
index b8ff5ca..c9375fa 100644
--- a/protobuf/listener.lua
+++ b/protobuf/listener.lua
@@ -18,14 +18,14 @@
 
 local setmetatable = setmetatable
 
-module "protobuf.listener"
+local listener = {}
 
 local _null_listener = {
   Modified = function()
   end
 }
 
-function NullMessageListener()
+function listener.NullMessageListener()
   return _null_listener
 end
 
@@ -41,10 +41,12 @@ local _listener_meta = {
 }
 _listener_meta.__index = _listener_meta
 
-function Listener(parent_message)
+function listener.Listener(parent_message)
   local o = {}
   o.__mode = "v"
   o._parent_message = parent_message
   o.dirty = false
   return setmetatable(o, _listener_meta)
 end
+
+return listener
\ No newline at end of file
diff --git a/protobuf/text_format.lua b/protobuf/text_format.lua
index 51fcde7..4902d6e 100644
--- a/protobuf/text_format.lua
+++ b/protobuf/text_format.lua
@@ -26,9 +26,9 @@ local tostring = tostring
 
 local descriptor = require "protobuf.descriptor"
 
-module "protobuf.text_format"
+local text_format = {}
 
-function format(buffer)
+function text_format.format(buffer)
   local len = string.len( buffer )
   for i = 1, len, 16 do
     local text = ""
@@ -41,7 +41,7 @@ end
 
 local FieldDescriptor = descriptor.FieldDescriptor
 
-msg_format_indent = function(write, msg, indent)
+text_format.msg_format_indent = function(write, msg, indent)
   for field, value in msg:ListFields() do
     local print_field = function(field_value)
       local name = field.name
@@ -53,7 +53,7 @@ msg_format_indent = function(write, msg, indent)
         else
           write(name .. " {\n")
         end
-        msg_format_indent(write, field_value, indent + 4)
+        text_format.msg_format_indent(write, field_value, indent + 4)
         write(string.rep(" ", indent))
         write("}\n")
       else
@@ -70,11 +70,13 @@ msg_format_indent = function(write, msg, indent)
   end
 end
 
-function msg_format(msg)
+function text_format.msg_format(msg)
   local out = {}
   local write = function(value)
     out[#out + 1] = value
   end
-  msg_format_indent(write, msg, 0)
+  text_format.msg_format_indent(write, msg, 0)
   return table.concat(out)
 end
+
+return text_format
\ No newline at end of file
diff --git a/protobuf/type_checkers.lua b/protobuf/type_checkers.lua
index a00b342..4c26d1a 100644
--- a/protobuf/type_checkers.lua
+++ b/protobuf/type_checkers.lua
@@ -20,9 +20,9 @@ local type = type
 local error = error
 local string = string
 
-module "protobuf.type_checkers"
+local type_checkers = {}
 
-function TypeChecker(acceptable_types)
+function type_checkers.TypeChecker(acceptable_types)
   local acceptable_types = acceptable_types
   return function(proposed_value)
     local t = type(proposed_value)
@@ -33,7 +33,7 @@ function TypeChecker(acceptable_types)
   end
 end
 
-function Int32ValueChecker()
+function type_checkers.Int32ValueChecker()
   local _MIN = -2147483648
   local _MAX = 2147483647
   return function(proposed_value)
@@ -47,7 +47,7 @@ function Int32ValueChecker()
   end
 end
 
-function Uint32ValueChecker(IntValueChecker)
+function type_checkers.Uint32ValueChecker(IntValueChecker)
   local _MIN = 0
   local _MAX = 0xffffffff
   return function(proposed_value)
@@ -61,10 +61,12 @@ function Uint32ValueChecker(IntValueChecker)
   end
 end
 
-function UnicodeValueChecker()
+function type_checkers.UnicodeValueChecker()
   return function (proposed_value)
     if type(proposed_value) ~= 'string' then
       error(string.format('%s has type %s, but expected one of: string', proposed_value, type(proposed_value)))
     end
   end
 end
+
+return type_checkers
\ No newline at end of file
diff --git a/protobuf/wire_format.lua b/protobuf/wire_format.lua
index 810ff43..6b04125 100644
--- a/protobuf/wire_format.lua
+++ b/protobuf/wire_format.lua
@@ -18,15 +18,15 @@
 
 local pb = require "protobuf.pb"
 
-module "protobuf.wire_format"
+local wire_format = {}
 
-WIRETYPE_VARINT = 0
-WIRETYPE_FIXED64 = 1
-WIRETYPE_LENGTH_DELIMITED = 2
-WIRETYPE_START_GROUP = 3
-WIRETYPE_END_GROUP = 4
-WIRETYPE_FIXED32 = 5
-_WIRETYPE_MAX = 5
+wire_format.WIRETYPE_VARINT = 0
+wire_format.WIRETYPE_FIXED64 = 1
+wire_format.WIRETYPE_LENGTH_DELIMITED = 2
+wire_format.WIRETYPE_START_GROUP = 3
+wire_format.WIRETYPE_END_GROUP = 4
+wire_format.WIRETYPE_FIXED32 = 5
+wire_format._WIRETYPE_MAX = 5
 
 -- we don't need uint64
 local function _VarUInt64ByteSizeNoTag(uint64)
@@ -37,94 +37,94 @@ local function _VarUInt64ByteSizeNoTag(uint64)
   return 5
 end
 
-function PackTag(field_number, wire_type)
+function wire_format.PackTag(field_number, wire_type)
   return field_number * 8 + wire_type
 end
 
-function UnpackTag(tag)
+function wire_format.UnpackTag(tag)
   local wire_type = tag % 8
   return (tag - wire_type) / 8, wire_type
 end
 
-ZigZagEncode32 = pb.zig_zag_encode32
-ZigZagDecode32 = pb.zig_zag_decode32
-ZigZagEncode64 = pb.zig_zag_encode64
-ZigZagDecode64 = pb.zig_zag_decode64
+wire_format.ZigZagEncode32 = pb.zig_zag_encode32
+wire_format.ZigZagDecode32 = pb.zig_zag_decode32
+wire_format.ZigZagEncode64 = pb.zig_zag_encode64
+wire_format.ZigZagDecode64 = pb.zig_zag_decode64
 
-function Int32ByteSize(field_number, int32)
-  return Int64ByteSize(field_number, int32)
+function wire_format.Int32ByteSize(field_number, int32)
+  return wire_format.Int64ByteSize(field_number, int32)
 end
 
-function Int32ByteSizeNoTag(int32)
+function wire_format.Int32ByteSizeNoTag(int32)
   return _VarUInt64ByteSizeNoTag(int32)
 end
 
-function Int64ByteSize(field_number, int64)
-  return UInt64ByteSize(field_number, int64)
+function wire_format.Int64ByteSize(field_number, int64)
+  return wire_format.UInt64ByteSize(field_number, int64)
 end
 
-function UInt32ByteSize(field_number, uint32)
-  return UInt64ByteSize(field_number, uint32)
+function wire_format.UInt32ByteSize(field_number, uint32)
+  return wire_format.UInt64ByteSize(field_number, uint32)
 end
 
-function UInt64ByteSize(field_number, uint64)
-  return TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(uint64)
+function wire_format.UInt64ByteSize(field_number, uint64)
+  return wire_format.TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(uint64)
 end
 
-function SInt32ByteSize(field_number, int32)
-  return UInt32ByteSize(field_number, ZigZagEncode(int32))
+function wire_format.SInt32ByteSize(field_number, int32)
+  return wire_format.UInt32ByteSize(field_number, wire_format.ZigZagEncode(int32))
 end
 
-function SInt64ByteSize(field_number, int64)
-  return UInt64ByteSize(field_number, ZigZagEncode(int64))
+function wire_format.SInt64ByteSize(field_number, int64)
+  return wire_format.UInt64ByteSize(field_number, wire_format.ZigZagEncode(int64))
 end
 
-function Fixed32ByteSize(field_number, fixed32)
-  return TagByteSize(field_number) + 4
+function wire_format.Fixed32ByteSize(field_number, fixed32)
+  return wire_format.TagByteSize(field_number) + 4
 end
 
-function Fixed64ByteSize(field_number, fixed64)
-  return TagByteSize(field_number) + 8
+function wire_format.Fixed64ByteSize(field_number, fixed64)
+  return wire_format.TagByteSize(field_number) + 8
 end
 
-function SFixed32ByteSize(field_number, sfixed32)
-  return TagByteSize(field_number) + 4
+function wire_format.SFixed32ByteSize(field_number, sfixed32)
+  return wire_format.TagByteSize(field_number) + 4
 end
 
-function SFixed64ByteSize(field_number, sfixed64)
-  return TagByteSize(field_number) + 8
+function wire_format.SFixed64ByteSize(field_number, sfixed64)
+  return wire_format.TagByteSize(field_number) + 8
 end
 
-function FloatByteSize(field_number, flt)
-  return TagByteSize(field_number) + 4
+function wire_format.FloatByteSize(field_number, flt)
+  return wire_format.TagByteSize(field_number) + 4
 end
 
-function DoubleByteSize(field_number, double)
-  return TagByteSize(field_number) + 8
+function wire_format.DoubleByteSize(field_number, double)
+  return wire_format.TagByteSize(field_number) + 8
 end
 
-function BoolByteSize(field_number, b)
-  return TagByteSize(field_number) + 1
+function wire_format.BoolByteSize(field_number, b)
+  return wire_format.TagByteSize(field_number) + 1
 end
 
-function EnumByteSize(field_number, enum)
-  return UInt32ByteSize(field_number, enum)
+function wire_format.EnumByteSize(field_number, enum)
+  return wire_format.UInt32ByteSize(field_number, enum)
 end
 
-function StringByteSize(field_number, string)
-  return BytesByteSize(field_number, string)
+function wire_format.StringByteSize(field_number, string)
+  return wire_format.BytesByteSize(field_number, string)
 end
 
-function BytesByteSize(field_number, b)
-  return TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(#b) + #b
+function wire_format.BytesByteSize(field_number, b)
+  return wire_format.TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(#b) + #b
 end
 
-function MessageByteSize(field_number, message)
-  return TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(message.ByteSize()) + message.ByteSize()
+function wire_format.MessageByteSize(field_number, message)
+  return wire_format.TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(message.ByteSize()) + message.ByteSize()
 end
 
-function MessageSetItemByteSize(field_number, msg)
-  local total_size = 2 * TagByteSize(1) + TagByteSize(2) + TagByteSize(3)
+function wire_format.MessageSetItemByteSize(field_number, msg)
+  local total_size = 2 * wire_format.TagByteSize(1) + wire_format.TagByteSize(2) + wire_format.TagByteSize(3)
   total_size = total_size + _VarUInt64ByteSizeNoTag(field_number)
   local message_size = msg.ByteSize()
   total_size = total_size + _VarUInt64ByteSizeNoTag(message_size)
@@ -132,6 +132,8 @@ function MessageSetItemByteSize(field_number, msg)
   return total_size
 end
 
-function TagByteSize(field_number)
-  return _VarUInt64ByteSizeNoTag(PackTag(field_number, 0))
+function wire_format.TagByteSize(field_number)
+  return _VarUInt64ByteSizeNoTag(wire_format.PackTag(field_number, 0))
 end
+
+return wire_format
\ No newline at end of file
diff --git a/protoc-plugin/protoc-gen-lua b/protoc-plugin/protoc-gen-lua
index b9bdeb3..efa2dd4 100755
--- a/protoc-plugin/protoc-gen-lua
+++ b/protoc-plugin/protoc-gen-lua
@@ -275,7 +275,7 @@ def code_gen_enum(enum_desc, env):
 
     values = []
     for i, enum_value in enumerate(enum_desc.value):
-        values.append(code_gen_enum_item(i, enum_value, env))
+        values.append('module.'+code_gen_enum_item(i, enum_value, env))
     context('.values = {%s}\n' % ','.join(values))
 
     env.context.append(context.getvalue())
@@ -303,6 +303,8 @@ def code_gen_field(index, field_desc, env):
         value = field_desc.default_value
         if field_desc.type == FDP.TYPE_STRING:
             context('.default_value = \'%s\'\n'%value)
+        elif field_desc.type == FDP.TYPE_ENUM:
+            context('.default_value = module.%s\n'%value)
         else:
             context('.default_value = %s\n'%value)
     else:
@@ -326,7 +328,7 @@ def code_gen_field(index, field_desc, env):
     if field_desc.HasField('extendee'):
         type_name = env.get_ref_name(field_desc.extendee)
         env.register.append(
-            '%s.RegisterExtension(%s)\n' % (type_name, obj_name)
+            'module.%s.RegisterExtension(module.%s)\n' % (type_name, obj_name)
         )
 
     context('.type = %d\n' % field_desc.type)
@@ -373,7 +375,7 @@ def code_gen_message(message_descriptor, env, containing_type = None):
     context('.extensions = {%s}\n' % ', '.join(extensions))
 
     if containing_type:
-        context('.containing_type = %s\n' % containing_type)
+        context('.containing_type = module.%s\n' % containing_type)
 
     env.message.append('module.%s = protobuf.Message(%s)\n' % (full_name, 'module.%s' % obj_name))