diff --git a/test_xvfb.py b/test_xvfb.py
index aa0420e..f8b19a1 100644
--- a/test_xvfb.py
+++ b/test_xvfb.py
@@ -64,7 +64,7 @@ def test_start_with_kwargs(self):
         self.assertEqual(display_var, os.environ['DISPLAY'])
         self.assertIsNotNone(xvfb.proc)
 
-    def test_start_with_arbitrary_kwargs(self):
+    def test_start_with_arbitrary_binary_kwargs(self):
         xvfb = Xvfb(nolisten='tcp')
         self.addCleanup(xvfb.stop)
         xvfb.start()
@@ -72,6 +72,14 @@ def test_start_with_arbitrary_kwargs(self):
         self.assertEqual(display_var, os.environ['DISPLAY'])
         self.assertIsNotNone(xvfb.proc)
 
+    def test_start_with_arbitrary_unary_kwargs(self):
+        xvfb = Xvfb(noreset=None)
+        self.addCleanup(xvfb.stop)
+        xvfb.start()
+        display_var = ':{}'.format(xvfb.new_display)
+        self.assertEqual(display_var, os.environ['DISPLAY'])
+        self.assertIsNotNone(xvfb.proc)
+
     def test_start_fails_with_unknown_kwargs(self):
         xvfb = Xvfb(foo='bar')
         with self.assertRaises(RuntimeError):
diff --git a/xvfbwrapper.py b/xvfbwrapper.py
index a2ad782..72fbecf 100644
--- a/xvfbwrapper.py
+++ b/xvfbwrapper.py
@@ -30,7 +30,10 @@ def __init__(self, width=800, height=680, colordepth=24, **kwargs):
                                 self.width, self.height, self.colordepth)]
 
         for key, value in kwargs.items():
-            self.extra_xvfb_args += ['-{}'.format(key), value]
+            if value:
+                self.extra_xvfb_args += ['-{}'.format(key), value]
+            else:
+                self.extra_xvfb_args.append('-{}'.format(key))
 
         if 'DISPLAY' in os.environ:
             self.orig_display = os.environ['DISPLAY'].split(':')[1]