diff --git a/trac-tracnav-plugin.spec b/trac-tracnav-plugin.spec
index 3432b33..5dad308 100644
--- a/trac-tracnav-plugin.spec
+++ b/trac-tracnav-plugin.spec
@@ -4,12 +4,13 @@
 
 Name:           trac-tracnav-plugin
 Version:        4.1
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Navigation Bar for Trac
 Group:          Applications/Internet
 License:        GPLv2+
 URL:            http://svn.ipd.uka.de/trac/javaparty/wiki/TracNav
 Source:         http://pypi.python.org/packages/source/T/TracNav/TracNav-%{version}.zip
+Patch0:         tracnav-4.1-trac-0.12-compat.patch
 BuildArch:      noarch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildRequires:  python-devel
@@ -28,6 +29,8 @@ that was originally supplied with Trac.
 
 %prep
 %setup -n %{tarname} -q
+# from r3276
+%patch0 -p0
 
 
 %build
@@ -50,6 +53,9 @@ rm -rf %{buildroot}
 
 
 %changelog
+* Fri Jan  7 2011 Thomas Moschny <thomas.moschny@gmx.de> - 4.1-4
+- Add patch from upstream for Trac 0.12 compatibility.
+
 * Thu Jul 22 2010 David Malcolm <dmalcolm@redhat.com> - 4.1-3
 - Rebuilt for https://fedoraproject.org/wiki/Features/Python_2.7/MassRebuild
 
diff --git a/tracnav-4.1-trac-0.12-compat.patch b/tracnav-4.1-trac-0.12-compat.patch
new file mode 100644
index 0000000..12fac0b
--- /dev/null
+++ b/tracnav-4.1-trac-0.12-compat.patch
@@ -0,0 +1,66 @@
+Index: README
+===================================================================
+--- README	(revision 3275)
++++ README	(revision 3276)
+@@ -66,7 +66,7 @@
+ -------------------
+ 
+ Copyright 2005-2006, Bernhard Haumacher (haui at haumacher.de)
+-Copyright 2005-2008, Thomas Moschny (thomas.moschny at gmx.de)
++Copyright 2005-2010, Thomas Moschny (thomas.moschny at gmx.de)
+ 
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+Index: tracnav/tracnav.py
+===================================================================
+--- tracnav/tracnav.py	(revision 3275)
++++ tracnav/tracnav.py	(revision 3276)
+@@ -34,7 +34,7 @@
+ == Author and License ==
+ 
+  * Copyright 2005-2006, Bernhard Haumacher (haui at haumacher.de)
+- * Copyright 2005-2008, Thomas Moschny (thomas.moschny at gmx.de)
++ * Copyright 2005-2010, Thomas Moschny (thomas.moschny at gmx.de)
+ 
+ {{{
+ This program is free software; you can redistribute it and/or modify
+@@ -63,6 +63,7 @@
+ from trac.wiki.model import WikiPage
+ from trac.wiki.formatter import Formatter, OneLinerFormatter
+ from trac.util.html import Markup
++from trac.util import arity
+ from genshi.builder import tag
+ from StringIO import StringIO
+ 
+@@ -87,6 +88,7 @@
+         OneLinerFormatter.__init__(self, env, ctx)
+         self.lastlink = None
+         self.allowed_macros = allowed_macros
++        self.mf_argcount = arity(OneLinerFormatter._macro_formatter)
+ 
+     def format_toc(self, wikitext):
+         self.lastlink = None
+@@ -100,14 +102,20 @@
+         return OneLinerFormatter._make_link(
+             self, namespace, target, *args)
+ 
+-    def _macro_formatter(self, match, fullmatch):
++    def _macro_formatter(self, match, fullmatch, macro=None):
+         name = fullmatch.group('macroname')
+         if name in self.allowed_macros:
+             # leapfrog the OneLinerFormatter
+-            return Formatter._macro_formatter(self, match, fullmatch)
++            if self.mf_argcount == 4:
++                return Formatter._macro_formatter(self, match, fullmatch, macro)
++            else:
++                return Formatter._macro_formatter(self, match, fullmatch)
+         else:
+             # use the OneLinerFormatter
+-            return OneLinerFormatter._macro_formatter(self, match, fullmatch)
++            if self.mf_argcount == 4:
++                return OneLinerFormatter._macro_formatter(self, match, fullmatch, macro)
++            else:
++                return OneLinerFormatter._macro_formatter(self, match, fullmatch)
+ 
+     # FIXME: what about _make_relative_link() ?
+     # FIXME: CamelCase links are special and not handled by the Formatter...