The usual
diff --git a/Lib/dos-8x3/test_ntp.py b/Lib/dos-8x3/test_ntp.py
index 1f824a5..11f2f44 100644
--- a/Lib/dos-8x3/test_ntp.py
+++ b/Lib/dos-8x3/test_ntp.py
@@ -1,5 +1,6 @@
 import ntpath
 import string
+import os
 
 errors = 0
 
@@ -34,6 +35,15 @@
 tester('ntpath.isabs("\\foo")', 1)
 tester('ntpath.isabs("\\foo\\bar")', 1)
 
+tester('ntpath.abspath("C:\\")', "C:\\")
+
+tester('ntpath.commonprefix(["/home/swenson/spam", "/home/swen/spam"])',
+       "/home/swen")
+tester('ntpath.commonprefix(["\\home\\swen\\spam", "\\home\\swen\\eggs"])',
+       "\\home\\swen\\")
+tester('ntpath.commonprefix(["/home/swen/spam", "/home/swen/spam"])',
+       "/home/swen/spam")
+
 if errors:
 	print str(errors) + " errors."
 else: