diff --git a/Lib/test/test_compare.py b/Lib/test/test_compare.py
index 9184355..1d8b947 100644
--- a/Lib/test/test_compare.py
+++ b/Lib/test/test_compare.py
@@ -44,5 +44,13 @@
                     print "%s == %s" % (a, b)
                 else:
                     print "%s != %s" % (a, b)
+    # Ensure default comparison compares id() of args
+    L = [None]
+    for i in range(10):
+        L.insert(len(L)/2, Empty())
+    for a in L:
+        for b in L:
+            if cmp(a, b) != cmp(id(a), id(b)):
+                print "ERROR:", cmp(a, b), cmp(id(a), id(b)), id(a), id(b)
 
 test()