Handle the case with zero arguments.
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 729cc3b..b32d953 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -104,6 +104,12 @@
             self.assertEqual(self.thetype('abcba').intersection(C('ccb')), set('bc'))
             self.assertEqual(self.thetype('abcba').intersection(C('ef')), set(''))
             self.assertEqual(self.thetype('abcba').intersection(C('cbcf'), C('bag')), set('b'))
+        s = self.thetype('abcba')
+        z = s.intersection()
+        if self.thetype == frozenset():
+            self.assertEqual(id(s), id(z))
+        else:
+            self.assertNotEqual(id(s), id(z))
 
     def test_isdisjoint(self):
         def f(s1, s2):
diff --git a/Objects/setobject.c b/Objects/setobject.c
index a892dc8..1127680 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1312,6 +1312,9 @@
 	Py_ssize_t i;
 	PyObject *result = (PyObject *)so;
 
+	if (PyTuple_GET_SIZE(args) == 0)
+		return set_copy(so);
+
 	Py_INCREF(so);
 	for (i=0 ; i<PyTuple_GET_SIZE(args) ; i++) {
 		PyObject *other = PyTuple_GET_ITEM(args, i);