diff --git a/lib/rdoc/generator/json_index.rb b/lib/rdoc/generator/json_index.rb
index ea9384e6d3..c63a0e591c 100644
--- a/lib/rdoc/generator/json_index.rb
+++ b/lib/rdoc/generator/json_index.rb
@@ -161,7 +161,7 @@ def generate
   # Compress the search_index.js file using gzip
 
   def generate_gzipped
-    return unless defined?(Zlib)
+    return if @options.dry_run or not defined?(Zlib)
 
     debug_msg "Compressing generated JSON index"
     out_dir = @base_dir + @options.op_dir
diff --git a/lib/rdoc/rdoc.rb b/lib/rdoc/rdoc.rb
index adcb65b13b..e0e28ddf97 100644
--- a/lib/rdoc/rdoc.rb
+++ b/lib/rdoc/rdoc.rb
@@ -521,13 +521,18 @@ def document options
   # by the RDoc options
 
   def generate
-    Dir.chdir @options.op_dir do
-      unless @options.quiet then
-        $stderr.puts "\nGenerating #{@generator.class.name.sub(/^.*::/, '')} format into #{Dir.pwd}..."
-      end
-
+    if @options.dry_run then
+      # do nothing
       @generator.generate
-      update_output_dir '.', @start_time, @last_modified
+    else
+      Dir.chdir @options.op_dir do
+        unless @options.quiet then
+          $stderr.puts "\nGenerating #{@generator.class.name.sub(/^.*::/, '')} format into #{Dir.pwd}..."
+        end
+
+        @generator.generate
+        update_output_dir '.', @start_time, @last_modified
+      end
     end
   end
 
diff --git a/test/test_rdoc_rdoc.rb b/test/test_rdoc_rdoc.rb
index be7a90c236..d5ce1639e4 100644
--- a/test/test_rdoc_rdoc.rb
+++ b/test/test_rdoc_rdoc.rb
@@ -40,6 +40,34 @@ def test_document # functional test
     assert_equal 'title',          store.title
   end
 
+  def test_document_with_dry_run # functional test
+    options = RDoc::Options.new
+    options.files = [File.expand_path('../xref_data.rb', __FILE__)]
+    options.setup_generator 'darkfish'
+    options.main_page = 'MAIN_PAGE.rdoc'
+    options.root      = Pathname File.expand_path('..', __FILE__)
+    options.title     = 'title'
+    options.dry_run = true
+
+    rdoc = RDoc::RDoc.new
+
+    out = nil
+    temp_dir do
+      out, = capture_io do
+        rdoc.document options
+      end
+
+      refute File.directory? 'doc'
+      assert_equal rdoc, rdoc.store.rdoc
+    end
+    assert_includes out, '100%'
+
+    store = rdoc.store
+
+    assert_equal 'MAIN_PAGE.rdoc', store.main
+    assert_equal 'title',          store.title
+  end
+
   def test_gather_files
     a = File.expand_path __FILE__
     b = File.expand_path '../test_rdoc_text.rb', __FILE__