diff --git a/doc/todo.txt b/doc/todo.txt
index 3f85e234..713ee171 100644
--- a/doc/todo.txt
+++ b/doc/todo.txt
@@ -1,2 +1 @@
-- Only run GUI tests when X server is available (ie. DISPLAY is set)
 - Port to Python 3.x (will not happen anytime soon though)
diff --git a/tests/__init__.py b/tests/__init__.py
index 195d5865..8a8f4e65 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -183,6 +183,14 @@ def has_pyqt ():
 need_pyqt = _need_func(has_pyqt, "PyQT")
 
 
+@memoized
+def has_x11 ():
+    """Test if DISPLAY variable is set."""
+    return os.getenv('DISPLAY') is not None
+
+need_x11 = _need_func(has_x11, 'X11')
+
+
 @contextmanager
 def _limit_time (seconds):
     """Raises LinkCheckerInterrupt if given number of seconds have passed."""
diff --git a/tests/test_gui.py b/tests/test_gui.py
index 7c9af0de..0c3ac8f4 100644
--- a/tests/test_gui.py
+++ b/tests/test_gui.py
@@ -16,13 +16,14 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 import unittest
 import sys
-from tests import need_pyqt
+from tests import need_pyqt, need_x11
 
 
 class TestGui (unittest.TestCase):
     """Test OMT GUI client."""
 
     @need_pyqt
+    @need_x11
     def test_gui (self):
         from PyQt4 import QtCore, QtGui, QtTest
         from linkcheck.gui import LinkCheckerMain