diff --git a/Doc/library/wsgiref.rst b/Doc/library/wsgiref.rst
--- a/Doc/library/wsgiref.rst
+++ b/Doc/library/wsgiref.rst
@@ -179,20 +179,21 @@ also provides these miscellaneous utilit
 .. module:: wsgiref.headers
    :synopsis: WSGI response header tools.
 
 
 This module provides a single class, :class:`Headers`, for convenient
 manipulation of WSGI response headers using a mapping-like interface.
 
 
-.. class:: Headers(headers)
+.. class:: Headers([headers])
 
    Create a mapping-like object wrapping *headers*, which must be a list of header
-   name/value tuples as described in :pep:`3333`.
+   name/value tuples as described in :pep:`3333`. The default value of *headers* is
+   an empty list.
 
    :class:`Headers` objects support typical mapping operations including
    :meth:`__getitem__`, :meth:`get`, :meth:`__setitem__`, :meth:`setdefault`,
    :meth:`__delitem__` and :meth:`__contains__`.  For each of
    these methods, the key is the header name (treated case-insensitively), and the
    value is the first value associated with that header name.  Setting a header
    deletes any existing values for that header, then adds a new value at the end of
    the wrapped header list.  Headers' existing order is generally maintained, with
@@ -246,16 +247,20 @@ manipulation of WSGI response headers us
 
          h.add_header('content-disposition', 'attachment', filename='bud.gif')
 
       The above will add a header that looks like this::
 
          Content-Disposition: attachment; filename="bud.gif"
 
 
+   .. versionchanged:: 3.5
+      The *headers* parameter is optional.
+
+
 :mod:`wsgiref.simple_server` -- a simple WSGI HTTP server
 ---------------------------------------------------------
 
 .. module:: wsgiref.simple_server
    :synopsis: A simple WSGI HTTP server.
 
 
 This module implements a simple HTTP server (based on :mod:`http.server`)
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -225,16 +225,22 @@ socket
 ------
 
 * New :meth:`socket.socket.sendfile` method allows to send a file over a socket
   by using high-performance :func:`os.sendfile` function on UNIX resulting in
   uploads being from 2x to 3x faster than when using plain
   :meth:`socket.socket.send`.
   (contributed by Giampaolo Rodola' in :issue:`17552`)
 
+wsgiref
+-------
+
+* The *headers* parameter of :class:`wsgiref.headers.Headers` is optional now.
+  (Contributed by Pablo Torres Navarrete and SilentGhost in :issue:`5800`.)
+
 xmlrpc
 ------
 
 * :class:`xmlrpc.client.ServerProxy` is now a :term:`context manager`
   (contributed by Claudiu Popa in :issue:`20627`).
 
 
 Optimizations
diff --git a/Lib/test/test_wsgiref.py b/Lib/test/test_wsgiref.py
--- a/Lib/test/test_wsgiref.py
+++ b/Lib/test/test_wsgiref.py
@@ -333,24 +333,25 @@ class UtilityTests(TestCase):
         ).split():
             for alt in hop, hop.title(), hop.upper(), hop.lower():
                 self.assertFalse(util.is_hop_by_hop(alt))
 
 class HeaderTests(TestCase):
 
     def testMappingInterface(self):
         test = [('x','y')]
+        self.assertEqual(len(Headers()), 0)
         self.assertEqual(len(Headers([])),0)
         self.assertEqual(len(Headers(test[:])),1)
         self.assertEqual(Headers(test[:]).keys(), ['x'])
         self.assertEqual(Headers(test[:]).values(), ['y'])
         self.assertEqual(Headers(test[:]).items(), test)
         self.assertIsNot(Headers(test).items(), test)  # must be copy!
 
-        h=Headers([])
+        h = Headers()
         del h['foo']   # should not raise an error
 
         h['Foo'] = 'bar'
         for m in h.__contains__, h.get, h.get_all, h.__getitem__:
             self.assertTrue(m('foo'))
             self.assertTrue(m('Foo'))
             self.assertTrue(m('FOO'))
             self.assertFalse(m('bar'))
@@ -365,19 +366,18 @@ class HeaderTests(TestCase):
         self.assertEqual(h.setdefault("foo","whee"), "baz")
         self.assertEqual(h.setdefault("zoo","whee"), "whee")
         self.assertEqual(h["foo"],"baz")
         self.assertEqual(h["zoo"],"whee")
 
     def testRequireList(self):
         self.assertRaises(TypeError, Headers, "foo")
 
-
     def testExtras(self):
-        h = Headers([])
+        h = Headers()
         self.assertEqual(str(h),'\r\n')
 
         h.add_header('foo','bar',baz="spam")
         self.assertEqual(h['foo'], 'bar; baz="spam"')
         self.assertEqual(str(h),'foo: bar; baz="spam"\r\n\r\n')
 
         h.add_header('Foo','bar',cheese=None)
         self.assertEqual(h.get_all('foo'),
diff --git a/Lib/wsgiref/headers.py b/Lib/wsgiref/headers.py
--- a/Lib/wsgiref/headers.py
+++ b/Lib/wsgiref/headers.py
@@ -21,20 +21,20 @@ def _formatparam(param, value=None, quot
             return '%s="%s"' % (param, value)
         else:
             return '%s=%s' % (param, value)
     else:
         return param
 
 
 class Headers:
-
     """Manage a collection of HTTP response headers"""
 
-    def __init__(self,headers):
+    def __init__(self, headers=None):
+        headers = headers or []
         if type(headers) is not list:
             raise TypeError("Headers must be a list of name/value tuples")
         self._headers = headers
         if __debug__:
             for k, v in headers:
                 self._convert_string_type(k)
                 self._convert_string_type(v)