diff --git a/glymur/test/test_jp2box_jpx.py b/glymur/test/test_jp2box_jpx.py
index d9d697b..f7cfec2 100644
--- a/glymur/test/test_jp2box_jpx.py
+++ b/glymur/test/test_jp2box_jpx.py
@@ -49,12 +49,16 @@ class TestJPXWrap(unittest.TestCase):
         """Rewrap a jpx file."""
         with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
             jpx = Jp2k(self.jpxfile)
-            idx = list(range(5)) + list(range(6, 9)) + list(range(9, 12)) + [12]
+            idx = list(range(5)) + list(range(9, 12)) + list(range(6, 9)) + [12]
             boxes = [jpx.box[j] for j in idx]
             jpx2 = jpx.wrap(tfile1.name, boxes=boxes)
             exp_ids = [box.box_id for box in boxes]
+            lengths = [box.length for box in jpx.box]
+            exp_lengths = [lengths[j] for j in idx]
         act_ids = [box.box_id for box in jpx2.box]
+        act_lengths = [box.length for box in jpx2.box]
         self.assertEqual(exp_ids, act_ids)
+        self.assertEqual(exp_lengths, act_lengths)
 
     def test_jpx_ftbl_no_codestream(self):
         """Can have a jpx with no codestream."""