diff -r 2a996cecf762 Lib/test/test_email/test_email.py
--- a/Lib/test/test_email/test_email.py	Thu Oct 31 05:55:31 2013 -0700
+++ b/Lib/test/test_email/test_email.py	Thu Oct 31 23:58:23 2013 +0800
@@ -26,6 +26,7 @@
 from email.mime.base import MIMEBase
 from email.mime.message import MIMEMessage
 from email.mime.multipart import MIMEMultipart
+from email.mime.nonmultipart import MIMENonMultipart
 from email import utils
 from email import errors
 from email import encoders
@@ -2604,6 +2605,19 @@
         self.assertTrue(msg.is_multipart())
 
 
+class TestNonMultipart(TestEmailBase):
+
+    def test_nonmultipart_is_not_multipart(self):
+        msg = MIMENonMultipart('text', 'plain')
+        self.assertFalse(msg.is_multipart())
+
+    def test_attach_raises_exception(self):
+        msg1 = Message()
+        msg1['Subject'] = 'subpart 1'
+        r = MIMENonMultipart('text', 'plain')
+        self.assertRaises(errors.MultipartConversionError, r.attach, msg1)
+
+
 # A general test of parser->model->generator idempotency.  IOW, read a message
 # in, parse it into a message object tree, then without touching the tree,
 # regenerate the plain text.  The original text and the transformed text