diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index b7f985c..4073d49 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -116,6 +116,10 @@
         ref1 = weakref.ref(c, callback)
         del c
 
+    def test_constructor_kwargs(self):
+        c = C()
+        self.assertRaises(TypeError, weakref.ref, c, callback=None)
+
     def test_proxy_ref(self):
         o = C()
         o.bar = 1