diff --git a/lib/rdoc/generator/darkfish.rb b/lib/rdoc/generator/darkfish.rb
index bd37b60668..2fd6007695 100644
--- a/lib/rdoc/generator/darkfish.rb
+++ b/lib/rdoc/generator/darkfish.rb
@@ -246,6 +246,7 @@ def generate
     generate_file_files
     generate_table_of_contents
     @json_index.generate
+    @json_index.generate_gzipped
 
     copy_static
 
diff --git a/lib/rdoc/generator/json_index.rb b/lib/rdoc/generator/json_index.rb
index c303b2effb..9d6f0d4356 100644
--- a/lib/rdoc/generator/json_index.rb
+++ b/lib/rdoc/generator/json_index.rb
@@ -1,4 +1,5 @@
 require 'json'
+require 'zlib'
 
 ##
 # The JsonIndex generator is designed to complement an HTML generator and
@@ -152,6 +153,49 @@ def generate
     end
   end
 
+  ##
+  # Compress the search_index.js file using gzip
+
+  def generate_gzipped
+    debug_msg "Compressing generated JSON index"
+    out_dir = @base_dir + @options.op_dir
+
+    search_index_file = out_dir + SEARCH_INDEX_FILE
+    outfile           = out_dir + "#{search_index_file}.gz"
+
+    debug_msg "Reading the JSON index file from %s" % search_index_file
+    search_index = search_index_file.read
+
+    debug_msg "Writing gzipped search index to %s" % outfile
+
+    Zlib::GzipWriter.open(outfile) do |gz|
+      gz.mtime = File.mtime(search_index_file)
+      gz.orig_name = search_index_file.to_s
+      gz.write search_index
+      gz.close
+    end
+
+    # GZip the rest of the js files
+    Dir.chdir @template_dir do
+      Dir['**/*.js'].each do |source|
+        dest = out_dir + source
+        outfile = out_dir + "#{dest}.gz"
+
+        debug_msg "Reading the original js file from %s" % dest
+        data = dest.read
+
+        debug_msg "Writing gzipped file to %s" % outfile
+
+        Zlib::GzipWriter.open(outfile) do |gz|
+          gz.mtime = File.mtime(dest)
+          gz.orig_name = dest.to_s
+          gz.write data
+          gz.close
+        end
+      end
+    end
+  end
+
   ##
   # Adds classes and modules to the index
 
diff --git a/test/test_rdoc_generator_json_index.rb b/test/test_rdoc_generator_json_index.rb
index 214e4a0d91..f25ee27d5e 100644
--- a/test/test_rdoc_generator_json_index.rb
+++ b/test/test_rdoc_generator_json_index.rb
@@ -136,6 +136,61 @@ def test_generate
     assert_equal expected, index
   end
 
+  def test_generate_gzipped
+    require 'zlib'
+    @g.generate
+    @g.generate_gzipped
+
+    assert_file 'js/searcher.js'
+    assert_file 'js/searcher.js.gz'
+    assert_file 'js/navigation.js'
+    assert_file 'js/navigation.js.gz'
+    assert_file 'js/search_index.js'
+    assert_file 'js/search_index.js.gz'
+
+    gzip = File.open 'js/search_index.js.gz'
+    json = Zlib::GzipReader.new(gzip).read
+
+    json =~ /\Avar search_data = /
+
+    assignment = $&
+    index = $'
+
+    refute_empty assignment
+
+    index = JSON.parse index
+
+    info = [
+      @klass.search_record[2..-1],
+      @nest_klass.search_record[2..-1],
+      @meth.search_record[2..-1],
+      @nest_meth.search_record[2..-1],
+      @page.search_record[2..-1],
+    ]
+
+    expected = {
+      'index' => {
+        'searchIndex' => [
+          'c',
+          'd',
+          'meth()',
+          'meth()',
+          'page',
+        ],
+        'longSearchIndex' => [
+          'c',
+          'c::d',
+          'c#meth()',
+          'c::d#meth()',
+          '',
+        ],
+        'info' => info,
+      },
+    }
+
+    assert_equal expected, index
+  end
+
   def test_generate_utf_8
     skip "Encoding not implemented" unless Object.const_defined? :Encoding