diff --git a/django/template/defaulttags.py b/django/template/defaulttags.py
index 318ae5ffd2..d629a690c5 100644
--- a/django/template/defaulttags.py
+++ b/django/template/defaulttags.py
@@ -157,15 +157,22 @@ class ForNode(Node):
             loop_dict['first'] = (i == 0)
             loop_dict['last'] = (i == len_values - 1)
 
+            pop_context = False
             if unpack:
                 # If there are multiple loop variables, unpack the item into
                 # them.
-                context.update(dict(zip(self.loopvars, item)))
+                try:
+                    unpacked_vars = dict(zip(self.loopvars, item))
+                except TypeError:
+                    pass
+                else:
+                    pop_context = True
+                    context.update(unpacked_vars)
             else:
                 context[self.loopvars[0]] = item
             for node in self.nodelist_loop:
                 nodelist.append(node.render(context))
-            if unpack:
+            if pop_context:
                 # The loop variables were pushed on to the context so pop them
                 # off again. This is necessary because the tag lets the length
                 # of loopvars differ to the length of each set of items and we
diff --git a/tests/regressiontests/templates/tests.py b/tests/regressiontests/templates/tests.py
index 2f2df65e96..bbbcae30eb 100644
--- a/tests/regressiontests/templates/tests.py
+++ b/tests/regressiontests/templates/tests.py
@@ -701,6 +701,7 @@ class Templates(unittest.TestCase):
             'for-tag-unpack11': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1), ('two', 2))}, ("one:1,/two:2,/", "one:1,INVALID/two:2,INVALID/")),
             'for-tag-unpack12': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2))}, ("one:1,carrot/two:2,/", "one:1,carrot/two:2,INVALID/")),
             'for-tag-unpack13': ("{% for x,y,z in items %}{{ x }}:{{ y }},{{ z }}/{% endfor %}", {"items": (('one', 1, 'carrot'), ('two', 2, 'cheese'))}, ("one:1,carrot/two:2,cheese/", "one:1,carrot/two:2,cheese/")),
+            'for-tag-unpack14': ("{% for x,y in items %}{{ x }}:{{ y }}/{% endfor %}", {"items": (1, 2)}, (":/:/", "INVALID:INVALID/INVALID:INVALID/")),
             'for-tag-empty01': ("{% for val in values %}{{ val }}{% empty %}empty text{% endfor %}", {"values": [1, 2, 3]}, "123"),
             'for-tag-empty02': ("{% for val in values %}{{ val }}{% empty %}values array empty{% endfor %}", {"values": []}, "values array empty"),
             'for-tag-empty03': ("{% for val in values %}{{ val }}{% empty %}values array not found{% endfor %}", {}, "values array not found"),