--- a/Lib/test/test_fcntl.py	Wed Mar 18 21:36:23 2015 -0500
+++ b/Lib/test/test_fcntl.py	Thu Mar 19 13:16:44 2015 +0200
@@ -70,6 +70,7 @@ class TestFcntl(unittest.TestCase):
         rv = fcntl.fcntl(self.f.fileno(), fcntl.F_SETLKW, lockdata)
         if verbose:
             print('String from fcntl with F_SETLKW: ', repr(rv))
+        fcntl.fcntl(self.f.fileno(), fcntl.F_SETLKW, bytearray(lockdata))
         self.f.close()
 
     def test_fcntl_file_descriptor(self):