diff --git a/CHANGES b/CHANGES
index ddf958f4e..235214e49 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,8 @@
 Release 1.0.8 (in development)
 ==============================
 
+* #693: Fix double encoding done when writing HTMLHelp .hhk files.
+
 * #647: Do not apply SmartyPants in parsed-literal blocks.
 
 
diff --git a/sphinx/builders/htmlhelp.py b/sphinx/builders/htmlhelp.py
index 2c9fe5303..9d367183a 100644
--- a/sphinx/builders/htmlhelp.py
+++ b/sphinx/builders/htmlhelp.py
@@ -258,7 +258,7 @@ class HTMLHelpBuilder(StandaloneHTMLBuilder):
             def write_index(title, refs, subitems):
                 def write_param(name, value):
                     item = '    <param name="%s" value="%s">\n' % (name, value)
-                    f.write(item.encode(self.encoding, 'xmlcharrefreplace'))
+                    f.write(item)
                 title = cgi.escape(title)
                 f.write('<LI> <OBJECT type="text/sitemap">\n')
                 write_param('Keyword', title)