diff --git a/django/utils/dateformat.py b/django/utils/dateformat.py
index 13cc2c7a81..efec5c35fe 100644
--- a/django/utils/dateformat.py
+++ b/django/utils/dateformat.py
@@ -128,7 +128,7 @@ class DateFormat(TimeFormat):
         ISO 8601 Format
         Example : '2008-01-02T10:30:00.000123'
         """
-        return self.data.isoformat(' ')
+        return self.data.isoformat()
 
     def d(self):
         "Day of the month, 2 digits with leading zeros; i.e. '01' to '31'"
diff --git a/docs/ref/templates/builtins.txt b/docs/ref/templates/builtins.txt
index 24c0af5699..393aab99e5 100644
--- a/docs/ref/templates/builtins.txt
+++ b/docs/ref/templates/builtins.txt
@@ -657,7 +657,7 @@ Available format strings:
     A                 ``'AM'`` or ``'PM'``.                     ``'AM'``
     b                 Month, textual, 3 letters, lowercase.     ``'jan'``
     B                 Not implemented.
-    c                 ISO 8601 Format.                          ``2008-01-02 10:30:00.000123``
+    c                 ISO 8601 Format.                          ``2008-01-02T10:30:00.000123``
     d                 Day of the month, 2 digits with           ``'01'`` to ``'31'``
                       leading zeros.
     D                 Day of the week, textual, 3 letters.      ``'Fri'``
diff --git a/tests/regressiontests/dateformat/tests.py b/tests/regressiontests/dateformat/tests.py
index 42c582cd0f..545b17d377 100644
--- a/tests/regressiontests/dateformat/tests.py
+++ b/tests/regressiontests/dateformat/tests.py
@@ -42,7 +42,7 @@ class DateFormatTests(TestCase):
         timestamp = datetime.datetime(2008, 5, 19, 11, 45, 23, 123456)
 
         self.assertEquals(dateformat.format(my_birthday, 'A'), u'PM')
-        self.assertEquals(dateformat.format(timestamp, 'c'), u'2008-05-19 11:45:23.123456')
+        self.assertEquals(dateformat.format(timestamp, 'c'), u'2008-05-19T11:45:23.123456')
         self.assertEquals(dateformat.format(my_birthday, 'd'), u'08')
         self.assertEquals(dateformat.format(my_birthday, 'j'), u'8')
         self.assertEquals(dateformat.format(my_birthday, 'l'), u'Sunday')