Index: Objects/unicodeobject.c
===================================================================
--- Objects/unicodeobject.c	(revision 71117)
+++ Objects/unicodeobject.c	(working copy)
@@ -6462,8 +6462,6 @@
     /* Coerce the two arguments */
     sub = PyUnicode_FromObject(element);
     if (!sub) {
-        PyErr_SetString(PyExc_TypeError,
-                        "'in <string>' requires string as left operand");
         return -1;
     }
 
Index: Lib/test/test_unicode.py
===================================================================
--- Lib/test/test_unicode.py	(revision 71117)
+++ Lib/test/test_unicode.py	(working copy)
@@ -345,6 +345,7 @@
         # the contains operator does not propagate UnicodeErrors or
         # someone has changed the default encoding
         self.assertRaises(UnicodeError, 'g\xe2teau'.__contains__, u'\xe2')
+        self.assertRaises(UnicodeError, u'g\xe2teau'.__contains__, '\xe2')
 
         self.assert_(u'' in '')
         self.assert_('' in u'')
@@ -375,6 +376,7 @@
         self.assert_(u'asdf' not in u'')
 
         self.assertRaises(TypeError, u"abc".__contains__)
+        self.assertRaises(TypeError, u"abc".__contains__, object())
 
     def test_formatting(self):
         string_tests.MixinStrUnicodeUserStringTest.test_formatting(self)