diff -r 19f36a2a34ec Lib/ntpath.py
--- a/Lib/ntpath.py	Mon Mar 23 01:09:35 2015 +0200
+++ b/Lib/ntpath.py	Mon Mar 23 09:27:53 2015 +0200
@@ -386,7 +386,7 @@ def expandvars(path):
                 index = path.index(c)
                 res += c + path[:index + 1]
             except ValueError:
-                res += path
+                res += c + path
                 index = pathlen - 1
         elif c == percent:  # variable or '%'
             if path[index + 1:index + 2] == percent:
diff -r 19f36a2a34ec Lib/test/test_ntpath.py
--- a/Lib/test/test_ntpath.py	Mon Mar 23 01:09:35 2015 +0200
+++ b/Lib/test/test_ntpath.py	Mon Mar 23 09:27:53 2015 +0200
@@ -237,6 +237,7 @@ class TestNtpath(unittest.TestCase):
             tester('ntpath.expandvars("%?bar%")', "%?bar%")
             tester('ntpath.expandvars("%foo%%bar")', "bar%bar")
             tester('ntpath.expandvars("\'%foo%\'%bar")', "\'%foo%\'%bar")
+            tester('ntpath.expandvars("bar\'%foo%")', "bar\'%foo%")
 
     @unittest.skipUnless(support.FS_NONASCII, 'need support.FS_NONASCII')
     def test_expandvars_nonascii(self):