diff --git a/History.txt b/History.txt
index 814b27380b..141dd93699 100644
--- a/History.txt
+++ b/History.txt
@@ -11,7 +11,7 @@
   * Locations of module aliases are now recorded.
   * RDoc::Parser::C finds method bodies better now.
   * Fixed further locations where output encoding was not preserved.  Bug #11
-    by Vít Ondruch.
+    by Vít Ondruch, RubyForge bug #28791 by Dzmitry Prakapenka.
   * Fixed display of numeric lists on the index page and file pages.  Bug #12
     by tobijk.
 
diff --git a/lib/rdoc/parser/ruby.rb b/lib/rdoc/parser/ruby.rb
index 61fc0f89f2..bdf02fd236 100644
--- a/lib/rdoc/parser/ruby.rb
+++ b/lib/rdoc/parser/ruby.rb
@@ -1641,8 +1641,11 @@ def read_documentation_modifiers(context, allow)
   # Removes private comments from +comment+
 
   def remove_private_comments(comment)
-    comment.gsub!(/^#--\n.*?^#\+\+\n?/m, '')
-    comment.sub!(/^#--\n.*\n?/m, '')
+    empty = ''
+    empty.force_encoding comment.encoding if Object.const_defined? :Encoding
+
+    comment.gsub!(/^#--\n.*?^#\+\+\n?/m, empty)
+    comment.sub!(/^#--\n.*\n?/m, empty)
   end
 
   ##
diff --git a/test/test_rdoc_parser_ruby.rb b/test/test_rdoc_parser_ruby.rb
index 7f23f3afa4..c13d672ee6 100644
--- a/test/test_rdoc_parser_ruby.rb
+++ b/test/test_rdoc_parser_ruby.rb
@@ -186,6 +186,23 @@ def test_remove_private_comments
     assert_equal expected, comment
   end
 
+  def test_remove_private_comments_encoding
+    skip "Encoding not implemented" unless Object.const_defined? :Encoding
+
+    util_parser ''
+
+    comment = <<-EOS
+# This is text
+#--
+# this is private
+    EOS
+    comment.force_encoding Encoding::IBM437
+
+    @parser.remove_private_comments comment
+
+    assert_equal Encoding::IBM437, comment.encoding
+  end
+
   def test_remove_private_comments_rule
     util_parser ''
 
@@ -223,6 +240,45 @@ def test_remove_private_comments_toggle
     assert_equal expected, comment
   end
 
+  def test_remove_private_comments_toggle_encoding
+    skip "Encoding not implemented" unless Object.const_defined? :Encoding
+
+    util_parser ''
+
+    comment = <<-EOS
+# This is text
+#--
+# this is private
+#++
+# This is text again.
+    EOS
+
+    comment.force_encoding Encoding::IBM437
+
+    @parser.remove_private_comments comment
+
+    assert_equal Encoding::IBM437, comment.encoding
+  end
+
+  def test_remove_private_comments_toggle_encoding_ruby_bug?
+    skip "Encoding not implemented" unless Object.const_defined? :Encoding
+
+    util_parser ''
+
+    comment = <<-EOS
+#--
+# this is private
+#++
+# This is text again.
+    EOS
+
+    comment.force_encoding Encoding::IBM437
+
+    @parser.remove_private_comments comment
+
+    assert_equal Encoding::IBM437, comment.encoding
+  end
+
   def test_look_for_directives_in_commented
     util_parser ""