Edited wiki page HowToSetupBuildbotForMelange through web user interface.
diff --git a/HowToSetupBuildbotForMelange.wiki b/HowToSetupBuildbotForMelange.wiki
index 6b1768a..e42da3a 100644
--- a/HowToSetupBuildbotForMelange.wiki
+++ b/HowToSetupBuildbotForMelange.wiki
@@ -13,7 +13,7 @@
   $ sudo pip install virtualenv
   $ sudo apt-get update
   $ sudo apt-get install libcurl4-gnutls-dev libexpat1-dev gettext libz-dev libssl-dev python-lxml python-dev 
-  $ sudo apt-get install libxml2-dev libxslt1-dev
+  $ sudo apt-get install libxml2-dev libxslt1-dev xvfb
   $ cd; mkdir buildbot; cd buildbot;
   $ virtualenv venv; cd venv;  . bin/activate
   $ pip install buildbot buildbot-slave