=== modified file 'setup.py'
--- setup.py	2012-04-10 12:10:55 +0000
+++ setup.py	2012-05-15 23:25:47 +0000
@@ -156,7 +156,8 @@
                              'zope.principalregistry',
                              'zope.testbrowser',
                              'schooltool.devtools>=0.6',
-                             'selenium'],
+                             'selenium',
+                             'pyvirtualdisplay'],
                     'docs': ['Sphinx',
                              'z3c.recipe.sphinxdoc'],
                     'apidoc': ['zope.app.apidoc'],

=== modified file 'src/schooltool/testing/selenium.py'
--- src/schooltool/testing/selenium.py	2012-03-26 14:57:09 +0000
+++ src/schooltool/testing/selenium.py	2012-05-15 23:07:51 +0000
@@ -33,6 +33,7 @@
 import unittest
 from StringIO import StringIO
 from UserDict import DictMixin
+from pyvirtualdisplay import Display

 import lxml.html
 import lxml.doctestcompare
@@ -966,6 +967,7 @@
     def __init__(self, *args, **kw):
         ZCMLLayer.__init__(self, *args, **kw)
         self.browsers = BrowserPool(self)
+        self.display = Display(visible=False, size=(800, 600))
         if BLACK_MAGIC:
             self.patches = []

@@ -988,6 +990,7 @@
         self.thread.start()
         print 'serving at http://%s:%s/' % (
             self.server.socket.getsockname())
+        self.display.start()

     def tearDown(self):
         self.serving = False
@@ -1002,6 +1005,7 @@
             snapshot = self.patches.pop()
             snapshot.restore()
             assert not self.patches
+        self.display.stop()

     def poll_server(self):
         self.serving = True