diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index d21d8ed..675aa5c 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -183,6 +183,16 @@ class TestBasicOps(unittest.TestCase):
         for proto in range(pickle.HIGHEST_PROTOCOL + 1):
             self.pickletest(proto, chain('abc', 'def'), compare=list('abcdef'))
 
+    def test_chain_setstate(self):
+        self.assertRaises(TypeError, chain().__setstate__, ())
+        self.assertRaises(SystemError, chain().__setstate__, ([]))
+        self.assertRaises(ValueError, chain().__setstate__, ([],))
+        self.assertRaises(ValueError, chain().__setstate__, ([], 0))
+        it = chain()
+        it.__setstate__((iter(['abc', 'def']),))
+        for x in it:
+            pass
+
     def test_combinations(self):
         self.assertRaises(TypeError, combinations, 'abc')       # missing r argument
         self.assertRaises(TypeError, combinations, 'abc', 2, 1) # too many arguments
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 62b6a0c..33abb0a 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -1906,6 +1906,11 @@ chain_setstate(chainobject *lz, PyObject *state)
     if (! PyArg_ParseTuple(state, "O|O", &source, &active))
         return NULL;
 
+    if (!PyIter_Check(source) || (active != NULL && !PyIter_Check(active))) {
+        PyErr_SetString(PyExc_ValueError, "Arguments must be iterators.");
+        return NULL;
+    }
+
     Py_INCREF(source);
     Py_XSETREF(lz->source, source);
     Py_XINCREF(active);