diff --git a/doc/config.rst b/doc/config.rst
index 804647681..ef66bda01 100644
--- a/doc/config.rst
+++ b/doc/config.rst
@@ -388,8 +388,6 @@ Options for HTML output
 These options influence HTML as well as HTML Help output, and other builders
 that use Sphinx' HTMLWriter class.
 
-.. XXX document html_context
-
 .. confval:: html_theme
 
    The "theme" that the HTML output should use.  See the :doc:`section about
@@ -437,6 +435,14 @@ that use Sphinx' HTMLWriter class.
 
    .. versionadded:: 0.4
 
+.. confval:: html_context
+
+   A dictionary of values to pass into the template engine's context for all
+   pages.  Single values can also be put in this dictionary using the
+   :option:`-A` command-line option of ``sphinx-build``.
+
+   .. versionadded:: 0.5
+
 .. confval:: html_logo
 
    If given, this must be the name of an image file that is the logo of the