diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index cdb158f311a..27bee619ea1 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -29,9 +29,9 @@ def tester(fn, wantResult):
 tester('posixpath.isabs("foo/bar")', 0)
 
 tester('posixpath.commonprefix(["/home/swenson/spam", "/home/swen/spam"])',
-       "/home")
-tester('posixpath.commonprefix(["/home/swen/spam", "/home/swen/eggs"])',
        "/home/swen")
+tester('posixpath.commonprefix(["/home/swen/spam", "/home/swen/eggs"])',
+       "/home/swen/")
 tester('posixpath.commonprefix(["/home/swen/spam", "/home/swen/spam"])',
        "/home/swen/spam")