diff --git a/doc/_static/psycopg.css b/doc/_static/psycopg.css
new file mode 100644
index 00000000..fd84ba09
--- /dev/null
+++ b/doc/_static/psycopg.css
@@ -0,0 +1,6 @@
+@import url("default.css");
+
+div.dbapi-extension {
+    background-color: #f5ffd4;
+    border: 1px solid #bda;
+}
diff --git a/doc/conf.py b/doc/conf.py
index 541de32b..51212139 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -22,7 +22,8 @@ import sys, os
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc', 'sphinx.ext.todo', 'sphinx.ext.ifconfig']
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.todo', 'sphinx.ext.ifconfig',
+        'dbapi_extension' ]
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -109,6 +110,10 @@ rst_epilog = """
 # Sphinx are currently 'default' and 'sphinxdoc'.
 html_theme = 'default'
 
+# The stylesheet to use with HTML output: this will include the original one
+# adding a few classes.
+html_style = 'psycopg.css'
+
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
diff --git a/doc/dbapi_extension.py b/doc/dbapi_extension.py
new file mode 100755
index 00000000..583c7523
--- /dev/null
+++ b/doc/dbapi_extension.py
@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+"""
+    extension
+    ~~~~~~~~~
+
+    A directive to create a box warning that a certain bit of Psycopg is an
+    extension to the DBAPI 2.0.
+
+    :copyright: Copyright 2010 by Daniele Varrazzo.
+"""
+
+from docutils import nodes
+
+from sphinx.util.compat import Directive, make_admonition
+
+class extension_node(nodes.Admonition, nodes.Element): pass
+
+
+class Extension(Directive):
+    """
+    An extension entry, displayed as an admonition.
+    """
+
+    has_content = True
+    required_arguments = 0
+    optional_arguments = 0
+    final_argument_whitespace = False
+    option_spec = {}
+
+    def run(self):
+        nodes = make_admonition(extension_node,
+                self.name, [_('DB API extension')], self.options,
+                self.content, self.lineno, self.content_offset,
+                self.block_text, self.state, self.state_machine)
+        nodes[0]['classes'].append('dbapi-extension')
+        return nodes
+
+
+def visit_extension_node(self, node):
+    self.visit_admonition(node)
+
+def depart_extension_node(self, node):
+    self.depart_admonition(node)
+
+def setup(app):
+    app.add_node(extension_node,
+                 html=(visit_extension_node, depart_extension_node),
+                 latex=(visit_extension_node, depart_extension_node),
+                 text=(visit_extension_node, depart_extension_node))
+
+    app.add_directive('extension', Extension)
+