diff --git a/en/upgrading.dbk b/en/upgrading.dbk
index 58d4bb8..4d0f0dc 100644
--- a/en/upgrading.dbk
+++ b/en/upgrading.dbk
@@ -1195,6 +1195,25 @@ See also <filename>/usr/share/doc/screen/NEWS.Debian.gz</filename> of
 Wheezy's <systemitem role="package">screen</systemitem> package.
 </para>
 </section>
+<section id="issues-puppet">
+<title>Puppet</title>
+<para>
+When upgrading a Puppet managed system from Squeeze to Wheezy, you
+must ensure that the corresponding puppetmaster runs at least Puppet
+version 2.7. If the master is running Squeeze's <systemitem
+role="package">puppetmaster</systemitem>, it is not recent enough
+and the managed Wheezy system will be unable to access the master. You
+can recgonize this situation by following error message during a
+<command>pupppet agent</command> run:
+</para>
+<screen>
+Could not retrieve catalog from remote server: Error 400 on SERVER: No support for http method POST
+</screen>
+<para>
+The only way to solve this problem is to upgrade the master. A 2.7
+master can manage a 2.6 client system.
+</para>
+</section>
 </section>
 <!-- End of 'trouble' section -->
 </section>