diff --git a/.gitignore b/.gitignore
index c02a141..3290571 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ pkg
 *.swo
 *.swp
 /Gemfile.lock
+/.rspec_status
diff --git a/lib/composite_io.rb b/lib/composite_io.rb
deleted file mode 100644
index 7fcdc70..0000000
--- a/lib/composite_io.rb
+++ /dev/null
@@ -1,108 +0,0 @@
-#--
-# Copyright (c) 2007-2012 Nick Sieger.
-# See the file README.txt included with the distribution for
-# software license details.
-#++
-
-# Concatenate together multiple IO objects into a single, composite IO object
-# for purposes of reading as a single stream.
-#
-# @example
-#     crio = CompositeReadIO.new(StringIO.new('one'),
-#                                StringIO.new('two'),
-#                                StringIO.new('three'))
-#     puts crio.read # => "onetwothree"
-class CompositeReadIO
-  # Create a new composite-read IO from the arguments, all of which should
-  # respond to #read in a manner consistent with IO.
-  def initialize(*ios)
-    @ios = ios.flatten
-    @index = 0
-  end
-
-  # Read from IOs in order until `length` bytes have been received.
-  def read(length = nil, outbuf = nil)
-    got_result = false
-    outbuf = outbuf ? outbuf.replace("") : ""
-
-    while io = current_io
-      if result = io.read(length)
-        got_result ||= !result.nil?
-        result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
-        outbuf << result
-        length -= result.length if length
-        break if length == 0
-      end
-      advance_io
-    end
-    (!got_result && length) ? nil : outbuf
-  end
-
-  def rewind
-    @ios.each { |io| io.rewind }
-    @index = 0
-  end
-
-  private
-
-  def current_io
-    @ios[@index]
-  end
-
-  def advance_io
-    @index += 1
-  end
-end
-
-# Convenience methods for dealing with files and IO that are to be uploaded.
-class UploadIO
-  attr_reader :content_type, :original_filename, :local_path, :io, :opts
-
-  # Create an upload IO suitable for including in the params hash of a
-  # Net::HTTP::Post::Multipart.
-  #
-  # Can take two forms. The first accepts a filename and content type, and
-  # opens the file for reading (to be closed by finalizer).
-  #
-  # The second accepts an already-open IO, but also requires a third argument,
-  # the filename from which it was opened (particularly useful/recommended if
-  # uploading directly from a form in a framework, which often save the file to
-  # an arbitrarily named RackMultipart file in /tmp).
-  #
-  # @example
-  #     UploadIO.new("file.txt", "text/plain")
-  #     UploadIO.new(file_io, "text/plain", "file.txt")
-  def initialize(filename_or_io, content_type, filename = nil, opts = {})
-    io = filename_or_io
-    local_path = ""
-    if io.respond_to? :read
-      # in Ruby 1.9.2, StringIOs no longer respond to path
-      # (since they respond to :length, so we don't need their local path, see parts.rb:41)
-      local_path = filename_or_io.respond_to?(:path) ? filename_or_io.path : "local.path"
-    else
-      io = File.open(filename_or_io)
-      local_path = filename_or_io
-    end
-    filename ||= local_path
-
-    @content_type = content_type
-    @original_filename = File.basename(filename)
-    @local_path = local_path
-    @io = io
-    @opts = opts
-  end
-
-  def self.convert!(io, content_type, original_filename, local_path)
-    raise ArgumentError, "convert! has been removed. You must now wrap IOs " \
-                         "using:\nUploadIO.new(filename_or_io, content_type, " \
-                         "filename=nil)\nPlease update your code."
-  end
-
-  def method_missing(*args)
-    @io.send(*args)
-  end
-
-  def respond_to?(meth, include_all = false)
-    @io.respond_to?(meth, include_all) || super(meth, include_all)
-  end
-end
diff --git a/lib/multipart_post.rb b/lib/multipart.rb
similarity index 77%
rename from lib/multipart_post.rb
rename to lib/multipart.rb
index 3a91cde..63bbf6e 100644
--- a/lib/multipart_post.rb
+++ b/lib/multipart.rb
@@ -4,6 +4,5 @@
 # software license details.
 #++
 
-module MultipartPost
-  VERSION = "2.1.1"
+module Multipart
 end
diff --git a/lib/multipart/post.rb b/lib/multipart/post.rb
new file mode 100644
index 0000000..f726be1
--- /dev/null
+++ b/lib/multipart/post.rb
@@ -0,0 +1,4 @@
+module Multipart
+  module Post
+  end
+end
diff --git a/lib/multipart/post/composite_read_io.rb b/lib/multipart/post/composite_read_io.rb
new file mode 100644
index 0000000..2e45fc3
--- /dev/null
+++ b/lib/multipart/post/composite_read_io.rb
@@ -0,0 +1,112 @@
+#--
+# Copyright (c) 2007-2012 Nick Sieger.
+# See the file README.txt included with the distribution for
+# software license details.
+#++
+
+# Concatenate together multiple IO objects into a single, composite IO object
+# for purposes of reading as a single stream.
+#
+# @example
+#     crio = CompositeReadIO.new(StringIO.new('one'),
+#                                StringIO.new('two'),
+#                                StringIO.new('three'))
+#     puts crio.read # => "onetwothree"
+module Multipart
+  module Post
+    class CompositeReadIO
+      # Create a new composite-read IO from the arguments, all of which should
+      # respond to #read in a manner consistent with IO.
+      def initialize(*ios)
+        @ios = ios.flatten
+        @index = 0
+      end
+
+      # Read from IOs in order until `length` bytes have been received.
+      def read(length = nil, outbuf = nil)
+        got_result = false
+        outbuf = outbuf ? outbuf.replace("") : ""
+
+        while io = current_io
+          if result = io.read(length)
+            got_result ||= !result.nil?
+            result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
+            outbuf << result
+            length -= result.length if length
+            break if length == 0
+          end
+          advance_io
+        end
+        (!got_result && length) ? nil : outbuf
+      end
+
+      def rewind
+        @ios.each { |io| io.rewind }
+        @index = 0
+      end
+
+      private
+
+      def current_io
+        @ios[@index]
+      end
+
+      def advance_io
+        @index += 1
+      end
+    end
+
+    # Convenience methods for dealing with files and IO that are to be uploaded.
+    class UploadIO
+      attr_reader :content_type, :original_filename, :local_path, :io, :opts
+
+      # Create an upload IO suitable for including in the params hash of a
+      # Net::HTTP::Post::Multipart.
+      #
+      # Can take two forms. The first accepts a filename and content type, and
+      # opens the file for reading (to be closed by finalizer).
+      #
+      # The second accepts an already-open IO, but also requires a third argument,
+      # the filename from which it was opened (particularly useful/recommended if
+      # uploading directly from a form in a framework, which often save the file to
+      # an arbitrarily named RackMultipart file in /tmp).
+      #
+      # @example
+      #     UploadIO.new("file.txt", "text/plain")
+      #     UploadIO.new(file_io, "text/plain", "file.txt")
+      def initialize(filename_or_io, content_type, filename = nil, opts = {})
+        io = filename_or_io
+        local_path = ""
+        if io.respond_to? :read
+          # in Ruby 1.9.2, StringIOs no longer respond to path
+          # (since they respond to :length, so we don't need their local path, see parts.rb:41)
+          local_path = filename_or_io.respond_to?(:path) ? filename_or_io.path : "local.path"
+        else
+          io = File.open(filename_or_io)
+          local_path = filename_or_io
+        end
+        filename ||= local_path
+
+        @content_type = content_type
+        @original_filename = File.basename(filename)
+        @local_path = local_path
+        @io = io
+        @opts = opts
+      end
+
+      def self.convert!(io, content_type, original_filename, local_path)
+        raise ArgumentError, "convert! has been removed. You must now wrap IOs " \
+          "using:\nUploadIO.new(filename_or_io, content_type, " \
+          "filename=nil)\nPlease update your code."
+      end
+
+      def method_missing(*args)
+        @io.send(*args)
+      end
+
+      def respond_to?(meth, include_all = false)
+        @io.respond_to?(meth, include_all) || super(meth, include_all)
+      end
+    end
+  end
+end
diff --git a/lib/multipart/post/multipartable.rb b/lib/multipart/post/multipartable.rb
new file mode 100644
index 0000000..27ba8ed
--- /dev/null
+++ b/lib/multipart/post/multipartable.rb
@@ -0,0 +1,53 @@
+#--
+# Copyright (c) 2007-2013 Nick Sieger.
+# See the file README.txt included with the distribution for
+# software license details.
+#++
+
+require 'multipart/post/parts'
+require 'multipart/post/composite_read_io'
+require 'securerandom'
+
+module Multipart
+  module Post
+    module Multipartable
+      def self.secure_boundary
+        # https://tools.ietf.org/html/rfc7230
+        #      tchar          = "!" / "#" / "$" / "%" / "&" / "'" / "*"
+        #                     / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
+        #                     / DIGIT / ALPHA
+
+        # https://tools.ietf.org/html/rfc2046
+        #      bcharsnospace := DIGIT / ALPHA / "'" / "(" / ")" /
+        #                       "+" / "_" / "," / "-" / "." /
+        #                       "/" / ":" / "=" / "?"
+
+        "--#{SecureRandom.uuid}"
+      end
+
+      def initialize(path, params, headers={}, boundary = Multipartable.secure_boundary)
+        headers = headers.clone # don't want to modify the original variable
+        parts_headers = headers.delete(:parts) || {}
+        super(path, headers)
+        parts = params.map do |k,v|
+          case v
+          when Array
+            v.map {|item| Parts::Part.new(boundary, k, item, parts_headers[k]) }
+          else
+            Parts::Part.new(boundary, k, v, parts_headers[k])
+          end
+        end.flatten
+        parts << Parts::EpiloguePart.new(boundary)
+        ios = parts.map {|p| p.to_io }
+        self.set_content_type(headers["Content-Type"] || "multipart/form-data",
+                              { "boundary" => boundary })
+        self.content_length = parts.inject(0) {|sum,i| sum + i.length }
+        self.body_stream = CompositeReadIO.new(*ios)
+
+        @boundary = boundary
+      end
+
+      attr :boundary
+    end
+  end
+end
diff --git a/lib/multipart/post/parts.rb b/lib/multipart/post/parts.rb
new file mode 100644
index 0000000..f14f80b
--- /dev/null
+++ b/lib/multipart/post/parts.rb
@@ -0,0 +1,131 @@
+#--
+# Copyright (c) 2007-2013 Nick Sieger.
+# See the file README.txt included with the distribution for
+# software license details.
+#++
+
+module Multipart
+  module Post
+    module Parts
+      module Part
+        def self.new(boundary, name, value, headers = {})
+          headers ||= {} # avoid nil values
+          if file?(value)
+            FilePart.new(boundary, name, value, headers)
+          else
+            ParamPart.new(boundary, name, value, headers)
+          end
+        end
+
+        def self.file?(value)
+          value.respond_to?(:content_type) && value.respond_to?(:original_filename)
+        end
+
+        def length
+          @part.length
+        end
+
+        def to_io
+          @io
+        end
+      end
+
+      # Represents a parametric part to be filled with given value.
+      class ParamPart
+        include Part
+
+        # @param boundary [String]
+        # @param name [#to_s]
+        # @param value [String]
+        # @param headers [Hash] Content-Type and Content-ID are used, if present.
+        def initialize(boundary, name, value, headers = {})
+          @part = build_part(boundary, name, value, headers)
+          @io = StringIO.new(@part)
+        end
+
+        def length
+          @part.bytesize
+        end
+
+        # @param boundary [String]
+        # @param name [#to_s]
+        # @param value [String]
+        # @param headers [Hash] Content-Type is used, if present.
+        def build_part(boundary, name, value, headers = {})
+          part = ''
+          part << "--#{boundary}\r\n"
+          part << "Content-ID: #{headers["Content-ID"]}\r\n" if headers["Content-ID"]
+          part << "Content-Disposition: form-data; name=\"#{name.to_s}\"\r\n"
+          part << "Content-Type: #{headers["Content-Type"]}\r\n" if headers["Content-Type"]
+          part << "\r\n"
+          part << "#{value}\r\n"
+        end
+      end
+
+      # Represents a part to be filled from file IO.
+      class FilePart
+        include Part
+
+        attr_reader :length
+
+        # @param boundary [String]
+        # @param name [#to_s]
+        # @param io [IO]
+        # @param headers [Hash]
+        def initialize(boundary, name, io, headers = {})
+          file_length = io.respond_to?(:length) ?  io.length : File.size(io.local_path)
+          @head = build_head(boundary, name, io.original_filename, io.content_type, file_length,
+                             io.respond_to?(:opts) ? io.opts.merge(headers) : headers)
+          @foot = "\r\n"
+          @length = @head.bytesize + file_length + @foot.length
+          @io = CompositeReadIO.new(StringIO.new(@head), io, StringIO.new(@foot))
+        end
+
+        # @param boundary [String]
+        # @param name [#to_s]
+        # @param filename [String]
+        # @param type [String]
+        # @param content_len [Integer]
+        # @param opts [Hash]
+        def build_head(boundary, name, filename, type, content_len, opts = {})
+          opts = opts.clone
+
+          trans_encoding = opts.delete("Content-Transfer-Encoding") || "binary"
+          content_disposition = opts.delete("Content-Disposition") || "form-data"
+
+          part = ''
+          part << "--#{boundary}\r\n"
+          part << "Content-Disposition: #{content_disposition}; name=\"#{name.to_s}\"; filename=\"#{filename}\"\r\n"
+          part << "Content-Length: #{content_len}\r\n"
+          if content_id = opts.delete("Content-ID")
+            part << "Content-ID: #{content_id}\r\n"
+          end
+
+          if opts["Content-Type"] != nil
+            part <<  "Content-Type: " + opts["Content-Type"] + "\r\n"
+          else
+            part << "Content-Type: #{type}\r\n"
+          end
+
+          part << "Content-Transfer-Encoding: #{trans_encoding}\r\n"
+
+          opts.each do |k, v|
+            part << "#{k}: #{v}\r\n"
+          end
+
+          part << "\r\n"
+        end
+      end
+
+      # Represents the epilogue or closing boundary.
+      class EpiloguePart
+        include Part
+
+        def initialize(boundary)
+          @part = "--#{boundary}--\r\n"
+          @io = StringIO.new(@part)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/multipart/post/version.rb b/lib/multipart/post/version.rb
new file mode 100644
index 0000000..cb5120c
--- /dev/null
+++ b/lib/multipart/post/version.rb
@@ -0,0 +1,5 @@
+module Multipart
+  module Post
+    VERSION = "2.1.1"
+  end
+end
diff --git a/lib/multipartable.rb b/lib/multipartable.rb
deleted file mode 100644
index 6a96575..0000000
--- a/lib/multipartable.rb
+++ /dev/null
@@ -1,48 +0,0 @@
-#--
-# Copyright (c) 2007-2013 Nick Sieger.
-# See the file README.txt included with the distribution for
-# software license details.
-#++
-
-require 'parts'
-require 'securerandom'
-
-module Multipartable
-  def self.secure_boundary
-    # https://tools.ietf.org/html/rfc7230
-    #      tchar          = "!" / "#" / "$" / "%" / "&" / "'" / "*"
-    #                     / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
-    #                     / DIGIT / ALPHA
-    
-    # https://tools.ietf.org/html/rfc2046
-    #      bcharsnospace := DIGIT / ALPHA / "'" / "(" / ")" /
-    #                       "+" / "_" / "," / "-" / "." /
-    #                       "/" / ":" / "=" / "?"
-    
-    "--#{SecureRandom.uuid}"
-  end
-  
-  def initialize(path, params, headers={}, boundary = Multipartable.secure_boundary)
-    headers = headers.clone # don't want to modify the original variable
-    parts_headers = headers.delete(:parts) || {}
-    super(path, headers)
-    parts = params.map do |k,v|
-      case v
-      when Array
-        v.map {|item| Parts::Part.new(boundary, k, item, parts_headers[k]) }
-      else
-        Parts::Part.new(boundary, k, v, parts_headers[k])
-      end
-    end.flatten
-    parts << Parts::EpiloguePart.new(boundary)
-    ios = parts.map {|p| p.to_io }
-    self.set_content_type(headers["Content-Type"] || "multipart/form-data",
-                          { "boundary" => boundary })
-    self.content_length = parts.inject(0) {|sum,i| sum + i.length }
-    self.body_stream = CompositeReadIO.new(*ios)
-    
-    @boundary = boundary
-  end
-  
-  attr :boundary
-end
diff --git a/lib/net/http/post/multipart.rb b/lib/net/http/post/multipart.rb
index dc53599..ac56097 100644
--- a/lib/net/http/post/multipart.rb
+++ b/lib/net/http/post/multipart.rb
@@ -7,21 +7,21 @@
 require 'net/http'
 require 'stringio'
 require 'cgi'
-require 'composite_io'
-require 'multipartable'
-require 'parts'
+require 'multipart/post/parts'
+require 'multipart/post/composite_read_io'
+require 'multipart/post/multipartable'
 
 module Net
   class HTTP
     class Put
       class Multipart < Put
-        include Multipartable
+        include ::Multipart::Post::Multipartable
       end
     end
 
     class Post
       class Multipart < Post
-        include Multipartable
+        include ::Multipart::Post::Multipartable
       end
     end
   end
diff --git a/lib/parts.rb b/lib/parts.rb
deleted file mode 100644
index 3382a18..0000000
--- a/lib/parts.rb
+++ /dev/null
@@ -1,127 +0,0 @@
-#--
-# Copyright (c) 2007-2013 Nick Sieger.
-# See the file README.txt included with the distribution for
-# software license details.
-#++
-
-module Parts
-  module Part
-    def self.new(boundary, name, value, headers = {})
-      headers ||= {} # avoid nil values
-      if file?(value)
-        FilePart.new(boundary, name, value, headers)
-      else
-        ParamPart.new(boundary, name, value, headers)
-      end
-    end
-
-    def self.file?(value)
-      value.respond_to?(:content_type) && value.respond_to?(:original_filename)
-    end
-
-    def length
-      @part.length
-    end
-
-    def to_io
-      @io
-    end
-  end
-
-  # Represents a parametric part to be filled with given value.
-  class ParamPart
-    include Part
-
-    # @param boundary [String]
-    # @param name [#to_s]
-    # @param value [String]
-    # @param headers [Hash] Content-Type and Content-ID are used, if present.
-    def initialize(boundary, name, value, headers = {})
-      @part = build_part(boundary, name, value, headers)
-      @io = StringIO.new(@part)
-    end
-
-    def length
-     @part.bytesize
-    end
-
-    # @param boundary [String]
-    # @param name [#to_s]
-    # @param value [String]
-    # @param headers [Hash] Content-Type is used, if present.
-    def build_part(boundary, name, value, headers = {})
-      part = ''
-      part << "--#{boundary}\r\n"
-      part << "Content-ID: #{headers["Content-ID"]}\r\n" if headers["Content-ID"]
-      part << "Content-Disposition: form-data; name=\"#{name.to_s}\"\r\n"
-      part << "Content-Type: #{headers["Content-Type"]}\r\n" if headers["Content-Type"]
-      part << "\r\n"
-      part << "#{value}\r\n"
-    end
-  end
-
-  # Represents a part to be filled from file IO.
-  class FilePart
-    include Part
-
-    attr_reader :length
-
-    # @param boundary [String]
-    # @param name [#to_s]
-    # @param io [IO]
-    # @param headers [Hash]
-    def initialize(boundary, name, io, headers = {})
-      file_length = io.respond_to?(:length) ?  io.length : File.size(io.local_path)
-      @head = build_head(boundary, name, io.original_filename, io.content_type, file_length,
-                         io.respond_to?(:opts) ? io.opts.merge(headers) : headers)
-      @foot = "\r\n"
-      @length = @head.bytesize + file_length + @foot.length
-      @io = CompositeReadIO.new(StringIO.new(@head), io, StringIO.new(@foot))
-    end
-
-    # @param boundary [String]
-    # @param name [#to_s]
-    # @param filename [String]
-    # @param type [String]
-    # @param content_len [Integer]
-    # @param opts [Hash]
-    def build_head(boundary, name, filename, type, content_len, opts = {})
-      opts = opts.clone
-
-      trans_encoding = opts.delete("Content-Transfer-Encoding") || "binary"
-      content_disposition = opts.delete("Content-Disposition") || "form-data"
-
-      part = ''
-      part << "--#{boundary}\r\n"
-      part << "Content-Disposition: #{content_disposition}; name=\"#{name.to_s}\"; filename=\"#{filename}\"\r\n"
-      part << "Content-Length: #{content_len}\r\n"
-      if content_id = opts.delete("Content-ID")
-        part << "Content-ID: #{content_id}\r\n"
-      end
-
-      if opts["Content-Type"] != nil
-        part <<  "Content-Type: " + opts["Content-Type"] + "\r\n"
-      else
-        part << "Content-Type: #{type}\r\n"
-      end
-
-      part << "Content-Transfer-Encoding: #{trans_encoding}\r\n"
-
-      opts.each do |k, v|
-        part << "#{k}: #{v}\r\n"
-      end
-
-      part << "\r\n"
-    end
-  end
-
-  # Represents the epilogue or closing boundary.
-  class EpiloguePart
-    include Part
-
-    def initialize(boundary)
-      @part = "--#{boundary}--\r\n"
-      @io = StringIO.new(@part)
-    end
-  end
-end
diff --git a/multipart-post.gemspec b/multipart-post.gemspec
index a3377f5..ef5fed1 100644
--- a/multipart-post.gemspec
+++ b/multipart-post.gemspec
@@ -1,10 +1,10 @@
 # -*- encoding: utf-8 -*-
 $:.push File.expand_path("../lib", __FILE__)
-require "multipart_post"
+require "multipart/post/version"
 
 Gem::Specification.new do |spec|
   spec.name        = "multipart-post"
-  spec.version     = MultipartPost::VERSION
+  spec.version     = Multipart::Post::VERSION
   spec.authors     = ["Nick Sieger", "Samuel Williams"]
   spec.email       = ["nick@nicksieger.com", "samuel.williams@oriontransfer.co.nz"]
   spec.homepage    = "https://github.com/nicksieger/multipart-post"
diff --git a/spec/multibyte.txt b/spec/fixtures/multibyte.txt
similarity index 100%
rename from spec/multibyte.txt
rename to spec/fixtures/multibyte.txt
diff --git a/spec/composite_io_spec.rb b/spec/multipart/post/composite_read_io_spec.rb
similarity index 58%
rename from spec/composite_io_spec.rb
rename to spec/multipart/post/composite_read_io_spec.rb
index c9409b3..5b03f7d 100644
--- a/spec/composite_io_spec.rb
+++ b/spec/multipart/post/composite_read_io_spec.rb
@@ -19,10 +19,12 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-require 'composite_io'
+require 'multipart/post/composite_read_io'
 require 'stringio'
 require 'timeout'
 
+MULTIBYTE = File.dirname(__FILE__) + '/../../fixtures/multibyte.txt'
+
 RSpec.shared_context "composite io" do
   it "test_full_read_from_several_ios" do
     expect(subject.read).to be == 'the quick brown fox'
@@ -80,59 +82,63 @@
   end
 end
 
-RSpec.describe CompositeReadIO do
-  describe "generic io" do
-    subject {StringIO.new('the quick brown fox')}
-  
-    include_context "composite io"
-  end
-  
-  describe "composite io" do
-    subject {CompositeReadIO.new(StringIO.new('the '), StringIO.new('quick '), StringIO.new('brown '), StringIO.new('fox'))}
-  
-    include_context "composite io"
-  end
-  
-  describe "nested composite io" do
-    subject {CompositeReadIO.new(CompositeReadIO.new(StringIO.new('the '), StringIO.new('quick ')), StringIO.new('brown '), StringIO.new('fox'))}
-  
-    include_context "composite io"
-  end
-  
-  describe "unicode composite io" do
-    let(:utf8_io) {File.open(File.dirname(__FILE__)+'/multibyte.txt')}
-    let(:binary_io) {StringIO.new("\x86")}
-    
-    subject {CompositeReadIO.new(binary_io, utf8_io)}
-    
-    it "test_read_from_multibyte" do
-      expect(subject.read).to be == "\x86\xE3\x83\x95\xE3\x82\xA1\xE3\x82\xA4\xE3\x83\xAB\n".b
-    end
-  end
-  
-  it "test_convert_error" do
-    expect do
-      UploadIO.convert!('tmp.txt', 'text/plain', 'tmp.txt', 'tmp.txt')
-    end.to raise_error(ArgumentError, /convert! has been removed/)
-  end
-  
-  it "test_empty" do
-    expect(subject.read).to be == ""
-  end
+module Multipart
+  module Post
+    RSpec.describe CompositeReadIO do
+      describe "generic io" do
+        subject {StringIO.new('the quick brown fox')}
 
-  it "test_empty_limited" do
-    expect(subject.read(1)).to be_nil
-  end
+        include_context "composite io"
+      end
 
-  it "test_empty_parts" do
-    io = CompositeReadIO.new(StringIO.new, StringIO.new('the '), StringIO.new, StringIO.new('quick'))
-    expect(io.read(3)).to be == "the"
-    expect(io.read(3)).to be == " qu"
-    expect(io.read(3)).to be == "ick"
-  end
+      describe "composite io" do
+        subject {CompositeReadIO.new(StringIO.new('the '), StringIO.new('quick '), StringIO.new('brown '), StringIO.new('fox'))}
+
+        include_context "composite io"
+      end
+
+      describe "nested composite io" do
+        subject {CompositeReadIO.new(CompositeReadIO.new(StringIO.new('the '), StringIO.new('quick ')), StringIO.new('brown '), StringIO.new('fox'))}
+
+        include_context "composite io"
+      end
+
+      describe "unicode composite io" do
+        let(:utf8_io) { File.open(MULTIBYTE) }
+        let(:binary_io) {StringIO.new("\x86")}
 
-  it "test_all_empty_parts" do
-    io = CompositeReadIO.new(StringIO.new, StringIO.new)
-    expect(io.read(1)).to be_nil
+        subject {CompositeReadIO.new(binary_io, utf8_io)}
+
+        it "test_read_from_multibyte" do
+          expect(subject.read).to be == "\x86\xE3\x83\x95\xE3\x82\xA1\xE3\x82\xA4\xE3\x83\xAB\n".b
+        end
+      end
+
+      it "test_convert_error" do
+        expect do
+          UploadIO.convert!('tmp.txt', 'text/plain', 'tmp.txt', 'tmp.txt')
+        end.to raise_error(ArgumentError, /convert! has been removed/)
+      end
+
+      it "test_empty" do
+        expect(subject.read).to be == ""
+      end
+
+      it "test_empty_limited" do
+        expect(subject.read(1)).to be_nil
+      end
+
+      it "test_empty_parts" do
+        io = CompositeReadIO.new(StringIO.new, StringIO.new('the '), StringIO.new, StringIO.new('quick'))
+        expect(io.read(3)).to be == "the"
+        expect(io.read(3)).to be == " qu"
+        expect(io.read(3)).to be == "ick"
+      end
+
+      it "test_all_empty_parts" do
+        io = CompositeReadIO.new(StringIO.new, StringIO.new)
+        expect(io.read(1)).to be_nil
+      end
+    end
   end
 end
diff --git a/spec/multipart/post/parts_spec.rb b/spec/multipart/post/parts_spec.rb
new file mode 100644
index 0000000..5c5d286
--- /dev/null
+++ b/spec/multipart/post/parts_spec.rb
@@ -0,0 +1,111 @@
+# Copyright, 2012, by Nick Sieger.
+# Copyright, 2017, by Samuel G. D. Williams. <http://www.codeotaku.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+require 'multipart/post/parts'
+require 'multipart/post/composite_read_io'
+require 'stringio'
+require 'tempfile'
+
+MULTIBYTE = File.dirname(__FILE__) + '/../../fixtures/multibyte.txt'
+TEMP_FILE = "temp.txt"
+
+module AssertPartLength
+  def assert_part_length(part)
+    bytes = part.to_io.read
+    bytesize = bytes.respond_to?(:bytesize) ? bytes.bytesize : bytes.length
+    expect(bytesize).to be == part.length
+  end
+end
+
+module Multipart
+  module Post
+    RSpec.describe Parts do
+      let(:string_with_content_type) do
+        Class.new(String) do
+          def content_type; 'application/data'; end
+        end
+      end
+
+      it "test_file_with_upload_io" do
+        expect(Parts::Part.file?(UploadIO.new(__FILE__, "text/plain"))).to be true
+      end
+
+      it "test_file_with_modified_string" do
+        expect(Parts::Part.file?(string_with_content_type.new("Hello"))).to be false
+      end
+
+      it "test_new_with_modified_string" do
+        expect(Parts::Part.new("boundary", "multibyte", string_with_content_type.new("Hello"))).to be_kind_of(Parts::ParamPart)
+      end
+    end
+
+    RSpec.describe Parts::FilePart do
+      include AssertPartLength
+
+      before(:each) do
+        File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
+        io =  UploadIO.new(TEMP_FILE, "text/plain")
+        @part = Parts::FilePart.new("boundary", "afile", io)
+      end
+
+      after(:each) do
+        File.delete(TEMP_FILE) rescue nil
+      end
+
+      it "test_correct_length" do
+        assert_part_length @part
+      end
+
+      it "test_multibyte_file_length" do
+        assert_part_length Parts::FilePart.new("boundary", "multibyte", UploadIO.new(MULTIBYTE, "text/plain"))
+      end
+
+      it "test_multibyte_filename" do
+        name = File.read(MULTIBYTE, 300)
+        file = Tempfile.new(name.respond_to?(:force_encoding) ? name.force_encoding("UTF-8") : name)
+        assert_part_length Parts::FilePart.new("boundary", "multibyte", UploadIO.new(file, "text/plain"))
+        file.close
+      end
+
+      it "test_force_content_type_header" do
+        part = Parts::FilePart.new("boundary", "afile", UploadIO.new(TEMP_FILE, "text/plain"), { "Content-Type" => "application/pdf" })
+        expect(part.to_io.read).to match(/Content-Type: application\/pdf/)
+      end
+    end
+
+    RSpec.describe Parts::ParamPart do
+      include AssertPartLength
+
+      before(:each) do
+        @part = Parts::ParamPart.new("boundary", "multibyte", File.read(MULTIBYTE))
+      end
+
+      it "test_correct_length" do
+        assert_part_length @part
+      end
+
+      it "test_content_id" do
+        part = Parts::ParamPart.new("boundary", "with_content_id", "foobar", "Content-ID" => "id")
+        expect(part.to_io.read).to match(/Content-ID: id/)
+      end
+    end
+  end
+end
diff --git a/spec/net/http/post/multipart_spec.rb b/spec/net/http/post/multipart_spec.rb
index a19ea04..3d6002e 100644
--- a/spec/net/http/post/multipart_spec.rb
+++ b/spec/net/http/post/multipart_spec.rb
@@ -60,19 +60,19 @@ def assert_additional_headers_added(post, parts_headers)
   it "test_form_multipart_body" do
     File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
     @io = File.open(TEMP_FILE)
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     assert_results Net::HTTP::Post::Multipart.new("/foo/bar", :foo => 'bar', :file => @io)
   end
 
   it "test_form_multipart_body_with_stringio" do
     @io = StringIO.new("1234567890")
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     assert_results Net::HTTP::Post::Multipart.new("/foo/bar", :foo => 'bar', :file => @io)
   end
 
   it "test_form_multiparty_body_with_parts_headers" do
     @io = StringIO.new("1234567890")
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     parts = { :text => 'bar', :file => @io }
     headers = {
       :parts => {
@@ -89,7 +89,7 @@ def assert_additional_headers_added(post, parts_headers)
   it "test_form_multipart_body_with_array_value" do
     File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
     @io = File.open(TEMP_FILE)
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     params = {:foo => ['bar', 'quux'], :file => @io}
     headers = { :parts => {
         :foo => { "Content-Type" => "application/json; charset=UTF-8" } } }
@@ -106,7 +106,7 @@ def assert_additional_headers_added(post, parts_headers)
   it "test_form_multipart_body_with_arrayparam" do
     File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
     @io = File.open(TEMP_FILE)
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     assert_results Net::HTTP::Post::Multipart.new("/foo/bar", :multivalueParam => ['bar','bah'], :file => @io)
   end
 end
@@ -117,7 +117,7 @@ def assert_additional_headers_added(post, parts_headers)
   it "test_form_multipart_body_put" do
     File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
     @io = File.open(TEMP_FILE)
-    @io = UploadIO.new @io, "text/plain", TEMP_FILE
+    @io = Multipart::Post::UploadIO.new @io, "text/plain", TEMP_FILE
     assert_results Net::HTTP::Put::Multipart.new("/foo/bar", :foo => 'bar', :file => @io)
   end
 end
diff --git a/spec/parts_spec.rb b/spec/parts_spec.rb
deleted file mode 100644
index b542c04..0000000
--- a/spec/parts_spec.rb
+++ /dev/null
@@ -1,107 +0,0 @@
-# Copyright, 2012, by Nick Sieger.
-# Copyright, 2017, by Samuel G. D. Williams. <http://www.codeotaku.com>
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-
-require 'parts'
-require 'stringio'
-require 'composite_io'
-require 'tempfile'
-
-MULTIBYTE = File.dirname(__FILE__)+'/multibyte.txt'
-TEMP_FILE = "temp.txt"
-
-module AssertPartLength
-  def assert_part_length(part)
-    bytes = part.to_io.read
-    bytesize = bytes.respond_to?(:bytesize) ? bytes.bytesize : bytes.length
-    expect(bytesize).to be == part.length
-  end
-end
-
-RSpec.describe Parts do
-  let(:string_with_content_type) do
-    Class.new(String) do
-      def content_type; 'application/data'; end
-    end
-  end
-
-  it "test_file_with_upload_io" do
-    expect(Parts::Part.file?(UploadIO.new(__FILE__, "text/plain"))).to be true
-  end
-
-  it "test_file_with_modified_string" do
-    expect(Parts::Part.file?(string_with_content_type.new("Hello"))).to be false
-  end
-
-  it "test_new_with_modified_string" do
-    expect(Parts::Part.new("boundary", "multibyte", string_with_content_type.new("Hello"))).to be_kind_of(Parts::ParamPart)
-  end
-end
-
-RSpec.describe Parts::FilePart do
-  include AssertPartLength
-
-  before(:each) do
-    File.open(TEMP_FILE, "w") {|f| f << "1234567890"}
-    io =  UploadIO.new(TEMP_FILE, "text/plain")
-    @part = Parts::FilePart.new("boundary", "afile", io)
-  end
-
-  after(:each) do
-    File.delete(TEMP_FILE) rescue nil
-  end
-
-  it "test_correct_length" do
-    assert_part_length @part
-  end
-
-  it "test_multibyte_file_length" do
-    assert_part_length Parts::FilePart.new("boundary", "multibyte", UploadIO.new(MULTIBYTE, "text/plain"))
-  end
-
-  it "test_multibyte_filename" do
-    name = File.read(MULTIBYTE, 300)
-    file = Tempfile.new(name.respond_to?(:force_encoding) ? name.force_encoding("UTF-8") : name)
-    assert_part_length Parts::FilePart.new("boundary", "multibyte", UploadIO.new(file, "text/plain"))
-    file.close
-  end
-
-   it "test_force_content_type_header" do
-    part = Parts::FilePart.new("boundary", "afile", UploadIO.new(TEMP_FILE, "text/plain"), { "Content-Type" => "application/pdf" })
-    expect(part.to_io.read).to match(/Content-Type: application\/pdf/)
-  end
-end
-
-RSpec.describe Parts::ParamPart do
-  include AssertPartLength
-
-  before(:each) do
-    @part = Parts::ParamPart.new("boundary", "multibyte", File.read(MULTIBYTE))
-  end
-
-  it "test_correct_length" do
-    assert_part_length @part
-  end
-
-  it "test_content_id" do
-    part = Parts::ParamPart.new("boundary", "with_content_id", "foobar", "Content-ID" => "id")
-    expect(part.to_io.read).to match(/Content-ID: id/)
-  end
-end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index c52cf78..6082995 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -17,7 +17,7 @@
 end
 
 require "bundler/setup"
-require "multipart_post"
+require "multipart/post"
 
 RSpec.configure do |config|
 	# Enable flags like --only-failures and --next-failure