diff --git a/activesupport/lib/active_support/multibyte.rb b/activesupport/lib/active_support/multibyte.rb
index 57e8e24bf4..cabe073616 100644
--- a/activesupport/lib/active_support/multibyte.rb
+++ b/activesupport/lib/active_support/multibyte.rb
@@ -21,24 +21,5 @@ module ActiveSupport #:nodoc:
     def self.proxy_class
       @proxy_class ||= ActiveSupport::Multibyte::Chars
     end
-
-    # Regular expressions that describe valid byte sequences for a character
-    VALID_CHARACTER = {
-      # Borrowed from the Kconv library by Shinji KONO - (also as seen on the W3C site)
-      'UTF-8' => /\A(?:
-                  [\x00-\x7f]                                         |
-                  [\xc2-\xdf] [\x80-\xbf]                             |
-                  \xe0        [\xa0-\xbf] [\x80-\xbf]                 |
-                  [\xe1-\xef] [\x80-\xbf] [\x80-\xbf]                 |
-                  \xf0        [\x90-\xbf] [\x80-\xbf] [\x80-\xbf]     |
-                  [\xf1-\xf3] [\x80-\xbf] [\x80-\xbf] [\x80-\xbf]     |
-                  \xf4        [\x80-\x8f] [\x80-\xbf] [\x80-\xbf])\z /xn,
-      # Quick check for valid Shift-JIS characters, disregards the odd-even pairing
-      'Shift_JIS' => /\A(?:
-                  [\x00-\x7e\xa1-\xdf]                                     |
-                  [\x81-\x9f\xe0-\xef] [\x40-\x7e\x80-\x9e\x9f-\xfc])\z /xn
-    }
   end
-end
-
-require 'active_support/multibyte/utils'
\ No newline at end of file
+end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/multibyte/utils.rb b/activesupport/lib/active_support/multibyte/utils.rb
deleted file mode 100644
index bd6d4bad41..0000000000
--- a/activesupport/lib/active_support/multibyte/utils.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-# encoding: utf-8
-
-module ActiveSupport #:nodoc:
-  module Multibyte #:nodoc:
-    # Returns a regular expression that matches valid characters in the current encoding
-    def self.valid_character
-      VALID_CHARACTER[Encoding.default_external.to_s]
-    end
-
-    # Verifies the encoding of a string
-    def self.verify(string)
-      string.valid_encoding?
-    end
-
-    # Verifies the encoding of the string and raises an exception when it's not valid
-    def self.verify!(string)
-      raise EncodingError.new("Found characters with invalid encoding") unless verify(string)
-    end
-
-    # Removes all invalid characters from the string.
-    #
-    # Note: this method is a no-op in Ruby 1.9
-    def self.clean(string)
-      string
-    end
-  end
-end
diff --git a/activesupport/test/multibyte_utils_test.rb b/activesupport/test/multibyte_utils_test.rb
deleted file mode 100644
index f807492be0..0000000000
--- a/activesupport/test/multibyte_utils_test.rb
+++ /dev/null
@@ -1,93 +0,0 @@
-# encoding: utf-8
-
-require 'abstract_unit'
-require 'multibyte_test_helpers'
-
-class MultibyteUtilsTest < ActiveSupport::TestCase
-  include MultibyteTestHelpers
-
-  test "valid_character returns an expression for the current encoding" do
-    with_encoding('None') do
-      assert_nil ActiveSupport::Multibyte.valid_character
-    end
-    with_encoding('UTF8') do
-      assert_equal ActiveSupport::Multibyte::VALID_CHARACTER['UTF-8'], ActiveSupport::Multibyte.valid_character
-    end
-    with_encoding('SJIS') do
-      assert_equal ActiveSupport::Multibyte::VALID_CHARACTER['Shift_JIS'], ActiveSupport::Multibyte.valid_character
-    end
-  end
-
-  test "verify verifies ASCII strings are properly encoded" do
-    with_encoding('None') do
-      examples.each do |example|
-        assert ActiveSupport::Multibyte.verify(example)
-      end
-    end
-  end
-
-  test "verify verifies UTF-8 strings are properly encoded" do
-    with_encoding('UTF8') do
-      assert ActiveSupport::Multibyte.verify(example('valid UTF-8'))
-      assert !ActiveSupport::Multibyte.verify(example('invalid UTF-8'))
-    end
-  end
-
-  test "verify verifies Shift-JIS strings are properly encoded" do
-    with_encoding('SJIS') do
-      assert ActiveSupport::Multibyte.verify(example('valid Shift-JIS'))
-      assert !ActiveSupport::Multibyte.verify(example('invalid Shift-JIS'))
-    end
-  end
-
-  test "verify! raises an exception when it finds an invalid character" do
-    with_encoding('UTF8') do
-      assert_raises(ActiveSupport::Multibyte::EncodingError) do
-        ActiveSupport::Multibyte.verify!(example('invalid UTF-8'))
-      end
-    end
-  end
-
-  test "verify! doesn't raise an exception when the encoding is valid" do
-    with_encoding('UTF8') do
-      assert_nothing_raised do
-        ActiveSupport::Multibyte.verify!(example('valid UTF-8'))
-      end
-    end
-  end
-
-  test "clean is a no-op" do
-    with_encoding('UTF8') do
-      assert_equal example('invalid Shift-JIS'), ActiveSupport::Multibyte.clean(example('invalid Shift-JIS'))
-    end
-  end
-
-  private
-
-  STRINGS = {
-    'valid ASCII'       => [65, 83, 67, 73, 73].pack('C*'),
-    'invalid ASCII'     => [128].pack('C*'),
-    'valid UTF-8'       => [227, 129, 147, 227, 129, 171, 227, 129, 161, 227, 130, 143].pack('C*'),
-    'invalid UTF-8'     => [184, 158, 8, 136, 165].pack('C*'),
-    'valid Shift-JIS'   => [131, 122, 129, 91, 131, 128].pack('C*'),
-    'invalid Shift-JIS' => [184, 158, 8, 0, 255, 136, 165].pack('C*')
-  }
-
-  def example(key)
-    STRINGS[key].force_encoding(Encoding.default_external)
-  end
-
-  def examples
-    STRINGS.values.map { |s| s.force_encoding(Encoding.default_external) }
-  end
-
-  KCODE_TO_ENCODING = Hash.new(Encoding::BINARY).
-    update('UTF8' => Encoding::UTF_8, 'SJIS' => Encoding::Shift_JIS)
-
-  def with_encoding(enc)
-    before = Encoding.default_external
-    silence_warnings { Encoding.default_external = KCODE_TO_ENCODING[enc] }
-    yield
-    silence_warnings { Encoding.default_external = before }
-  end
-end