diff --git a/django/template/defaultfilters.py b/django/template/defaultfilters.py
index 739f50f235..b0b094bb70 100644
--- a/django/template/defaultfilters.py
+++ b/django/template/defaultfilters.py
@@ -601,6 +601,10 @@ def unordered_list(value, autoescape=None):
         first_item, second_item = list_
         if second_item == []:
             return [first_item], True
+        try:
+            it = iter(second_item)  # see if second item is iterable
+        except TypeError:
+            return list_, False
         old_style_list = True
         new_second_item = []
         for sublist in second_item:
diff --git a/tests/regressiontests/defaultfilters/tests.py b/tests/regressiontests/defaultfilters/tests.py
index 8341f83e36..50aaf212ed 100644
--- a/tests/regressiontests/defaultfilters/tests.py
+++ b/tests/regressiontests/defaultfilters/tests.py
@@ -347,6 +347,17 @@ u'\t<li>item 1\n\t<ul>\n\t\t<li>item 1.1\n\t\t<ul>\n\t\t\t<li>item 1.1.1\n\t\t\t
 >>> unordered_list(['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']])
 u'\t<li>States\n\t<ul>\n\t\t<li>Kansas\n\t\t<ul>\n\t\t\t<li>Lawrence</li>\n\t\t\t<li>Topeka</li>\n\t\t</ul>\n\t\t</li>\n\t\t<li>Illinois</li>\n\t</ul>\n\t</li>'
 
+>>> class ULItem(object):
+...     def __init__(self, title):
+...       self.title = title
+...     def __unicode__(self):
+...         return u'ulitem-%s' % str(self.title)
+
+>>> a = ULItem('a')
+>>> b = ULItem('b')
+>>> unordered_list([a,b])
+u'\t<li>ulitem-a</li>\n\t<li>ulitem-b</li>'
+
 # Old format for unordered lists should still work
 >>> unordered_list([u'item 1', []])
 u'\t<li>item 1</li>'