diff -r ee5123d6ab6c Objects/object.c
--- a/Objects/object.c	Wed Jan 02 11:56:58 2013 +0200
+++ b/Objects/object.c	Wed Jan 02 22:00:34 2013 +0900
@@ -491,6 +491,10 @@
     if (PyInstance_Check(v)) {
         /* We're an instance of a classic class */
         /* Try __unicode__ from the instance -- alas we have no type */
+        if (unicodestr == NULL)
+            unicodestr = PyString_InternFromString("__unicode__");
+        if (unicodestr == NULL)
+            return NULL;
         func = PyObject_GetAttr(v, unicodestr);
         if (func != NULL) {
             unicode_method_found = 1;