diff --git a/ChangeLog b/ChangeLog
index 8ba33abd8d..e2d5bae826 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Fri Oct  3 19:33:21 2008  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* ext/json/lib/json/pure.rb (module JSON): remove Iconv dependency.
+
+	* ext/json/lib/json/pure/generator.rb (utf8_to_json): process as
+	  binary and remove Iconv dependency.
+
+	* ext/json/lib/json/pure/parser.rb (parse_string): ditto.
+
 Fri Oct  3 14:04:05 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/{configure.bat,setup.mak,Makefile.sub): add --program-prefix
diff --git a/ext/json/lib/json/pure.rb b/ext/json/lib/json/pure.rb
index b86d905523..6af8705c5b 100644
--- a/ext/json/lib/json/pure.rb
+++ b/ext/json/lib/json/pure.rb
@@ -3,59 +3,6 @@ require 'json/pure/parser'
 require 'json/pure/generator'
 
 module JSON
-  begin
-    require 'iconv'
-    # An iconv instance to convert from UTF8 to UTF16 Big Endian.
-    UTF16toUTF8 = Iconv.new('utf-8', 'utf-16be') # :nodoc:
-    # An iconv instance to convert from UTF16 Big Endian to UTF8.
-    UTF8toUTF16 = Iconv.new('utf-16be', 'utf-8') # :nodoc:
-    UTF8toUTF16.iconv('no bom')
-  rescue Errno::EINVAL, Iconv::InvalidEncoding
-    # Iconv doesn't support big endian utf-16. Let's try to hack this manually
-    # into the converters.
-    begin
-      old_verbose, $VERBSOSE = $VERBOSE, nil
-      # An iconv instance to convert from UTF8 to UTF16 Big Endian.
-      UTF16toUTF8 = Iconv.new('utf-8', 'utf-16') # :nodoc:
-      # An iconv instance to convert from UTF16 Big Endian to UTF8.
-      UTF8toUTF16 = Iconv.new('utf-16', 'utf-8') # :nodoc:
-      UTF8toUTF16.iconv('no bom')
-      if UTF8toUTF16.iconv("\xe2\x82\xac") == "\xac\x20"
-        swapper = Class.new do
-          def initialize(iconv) # :nodoc:
-            @iconv = iconv
-          end
-
-          def iconv(string) # :nodoc:
-            result = @iconv.iconv(string)
-            JSON.swap!(result)
-          end
-        end
-        UTF8toUTF16 = swapper.new(UTF8toUTF16) # :nodoc:
-      end
-      if UTF16toUTF8.iconv("\xac\x20") == "\xe2\x82\xac"
-        swapper = Class.new do
-          def initialize(iconv) # :nodoc:
-            @iconv = iconv
-          end
-
-          def iconv(string) # :nodoc:
-            string = JSON.swap!(string.dup)
-            @iconv.iconv(string)
-          end
-        end
-        UTF16toUTF8 = swapper.new(UTF16toUTF8) # :nodoc:
-      end
-    rescue Errno::EINVAL, Iconv::InvalidEncoding
-      raise MissingUnicodeSupport, "iconv doesn't seem to support UTF-8/UTF-16 conversions"
-    ensure
-      $VERBOSE = old_verbose
-    end
-  rescue LoadError
-    raise MissingUnicodeSupport,
-      "iconv couldn't be loaded, which is required for UTF-8/UTF-16 conversions"
-  end
-
   # Swap consecutive bytes of _string_ in place.
   def self.swap!(string) # :nodoc:
     0.upto(string.size / 2) do |i|
diff --git a/ext/json/lib/json/pure/generator.rb b/ext/json/lib/json/pure/generator.rb
index c8bbfd09ee..91bdc0ff41 100644
--- a/ext/json/lib/json/pure/generator.rb
+++ b/ext/json/lib/json/pure/generator.rb
@@ -41,6 +41,7 @@ module JSON
   # UTF16 big endian characters as \u????, and return it.
   def utf8_to_json(string) # :nodoc:
     string = string.gsub(/["\\\/\x0-\x1f]/) { MAP[$&] }
+    string.force_encoding(Encoding::ASCII_8BIT)
     string.gsub!(/(
                     (?:
                       [\xc2-\xdf][\x80-\xbf]    |
@@ -50,12 +51,10 @@ module JSON
                     [\x80-\xc1\xf5-\xff]       # invalid
                   )/nx) { |c|
       c.size == 1 and raise GeneratorError, "invalid utf8 byte: '#{c}'"
-      s = JSON::UTF8toUTF16.iconv(c).unpack('H*')[0]
-      s.gsub!(/.{4}/n, '\\\\u\&')
+      c = c.unpack("U*")[0]
+      c > 0xFFFF ? ('\uD%03X\uD%03X' % [0x7C0+c/1024, 0xC00+c%1024]) : ('\u%04X'%c)
     }
     string
-  rescue Iconv::Failure => e
-    raise GeneratorError, "Caught #{e.class}: #{e}"
   end
   module_function :utf8_to_json
 
diff --git a/ext/json/lib/json/pure/parser.rb b/ext/json/lib/json/pure/parser.rb
index 9b30f15c07..a0ab3075fe 100644
--- a/ext/json/lib/json/pure/parser.rb
+++ b/ext/json/lib/json/pure/parser.rb
@@ -126,20 +126,30 @@ module JSON
             if u = UNESCAPE_MAP[$&[1]]
               u
             else # \uXXXX
-              bytes = ''
-              i = 0
-              while c[6 * i] == ?\\ && c[6 * i + 1] == ?u 
-                bytes << c[6 * i + 2, 2].to_i(16) << c[6 * i + 4, 2].to_i(16)
-                i += 1
+              res = []
+              stack = nil
+              [c.delete!('\\\\u')].pack("H*").unpack("n*").each do |c|
+                case c
+                when 0xD800..0xDBFF
+                  raise JSON::ParserError, "partial character in source" if stack
+                  stack = c
+                when 0xDC00..0xDFFF
+                  raise JSON::ParserError,
+                    "partial character in source" unless (0xD800..0xDBFF).include?(stack)
+                  res << (stack << 10) - 0x35fdc00 + c
+                  stack = nil
+                else
+                  raise JSON::ParserError, "partial character in source" if stack
+                  res << c
+                end
               end
-              JSON::UTF16toUTF8.iconv(bytes)
+              raise JSON::ParserError, "partial character in source" if stack
+              res.pack("U*")
             end
           end
         else
           UNPARSED
         end
-      rescue Iconv::Failure => e
-        raise GeneratorError, "Caught #{e.class}: #{e}"
       end
 
       def parse_value