diff --git a/doc/developer-guidelines.sgml b/doc/developer-guidelines.sgml
index 599b2a16..eb5b0391 100644
--- a/doc/developer-guidelines.sgml
+++ b/doc/developer-guidelines.sgml
@@ -11,7 +11,7 @@
- 2009
+ 2013
Nagios plug-in development guidelines
@@ -22,7 +22,7 @@
- 2000 - 2009
+ 2000 - 2013
Nagios Plugins Development Team
@@ -34,7 +34,7 @@
the plug-in developers and encourage the standarization of the
different kind of plug-ins: C, shell, perl, python, etc.
- Nagios Plug-in Development Guidelines Copyright (C) 2000-2009
+ Nagios Plug-in Development Guidelines Copyright (C) 2000-2013
(Nagios Plugins Team)
Permission is granted to make and distribute verbatim