diff --git a/glymur/jp2box.py b/glymur/jp2box.py
index bf88e4d..6f628df 100644
--- a/glymur/jp2box.py
+++ b/glymur/jp2box.py
@@ -2122,6 +2122,7 @@ class UUIDBox(Jp2kBox):
                 text = raw_data.decode('utf-8')
                 elt = ET.fromstring(text)
             self.data = ET.ElementTree(elt)
+            self._type = 'XMP'
         elif the_uuid.bytes == b'JpgTiffExif->JP2':
             exif_obj = Exif(raw_data)
             ifds = OrderedDict()
@@ -2130,8 +2131,16 @@ class UUIDBox(Jp2kBox):
             ifds['GPSInfo'] = exif_obj.exif_gpsinfo
             ifds['Iop'] = exif_obj.exif_iop
             self.data = ifds
+            self._type = 'Exif'
         else:
             self.data = raw_data
+            self._type = 'unknown'
+
+        if length == 0:
+            # Need to compute the length.
+            # The length is 8 (L and T fields) + 16 (length of UUID identifier)
+            # + length of uuid data.
+            length = 24 + len(self.data)
 
         self.length = length
         self.offset = offset
@@ -2164,6 +2173,16 @@ class UUIDBox(Jp2kBox):
 
         return msg
 
+    def write(self, fptr):
+        """Write a UUID box box to file.
+        """
+        if self._type != 'XMP':
+            msg = "Only XMP UUID boxes can currently be written."
+            raise NotImplementedError(msg)
+        read_buffer = struct.pack('>I4s', self.length, 'uuid')
+        fptr.write(read_buffer)
+        fptr.write(self.data)
+
     @staticmethod
     def parse(fptr, offset, length):
         """Parse UUID box.
diff --git a/glymur/jp2k.py b/glymur/jp2k.py
index 1bd36a4..45eaf39 100644
--- a/glymur/jp2k.py
+++ b/glymur/jp2k.py
@@ -514,14 +514,17 @@ class Jp2k(Jp2kBox):
         Parameters
         ----------
         box : Jp2Box
-            Instance of a JP2 box.  Currently only XML boxes are allowed.
+            Instance of a JP2 box.  Only UUID and XML boxes can currently be
+            appended.
         """
         if self._codec_format == opj2.CODEC_J2K:
             msg = "Only JP2 files can currently have boxes appended to them."
             raise IOError(msg)
 
-        if box.box_id != 'xml ':
-            raise IOError("Only XML boxes can currently be appended.")
+        if not ((box.box_id == 'xml ') or
+                (box.box_id == 'uuid' and box._type == 'XMP')):
+            msg = "Only XML boxes and XMP UUID boxes can currently be appended."
+            raise IOError(msg)
 
         # Check the last box.  If the length field is zero, then rewrite
         # the length field to reflect the true length of the box.
diff --git a/glymur/test/test_jp2box.py b/glymur/test/test_jp2box.py
index ef62460..ff61bc5 100644
--- a/glymur/test/test_jp2box.py
+++ b/glymur/test/test_jp2box.py
@@ -429,14 +429,14 @@ class TestAppend(unittest.TestCase):
         with tempfile.NamedTemporaryFile(suffix=".j2k") as tfile:
             shutil.copyfile(self.j2kfile, tfile.name)
 
-            jp2 = Jp2k(tfile.name)
+            j2k = Jp2k(tfile.name)
 
-            # Make a UUID box.
-            uuid_instance = uuid.UUID('00000000-0000-0000-0000-000000000000')
-            data = b'0123456789'
-            uuidbox = glymur.jp2box.UUIDBox(uuid_instance, data)
+            # Make an XML box.  XML boxes should always be appendable to jp2
+            # files.
+            the_xml = ET.fromstring('<?xml version="1.0"?><data>0</data>')
+            xmlbox = glymur.jp2box.XMLBox(xml=the_xml)
             with self.assertRaises(IOError):
-                jp2.append(uuidbox)
+                j2k.append(xmlbox)
 
     def test_length_field_is_zero(self):
         """L=0 (length field in box header) is handled.
@@ -473,14 +473,14 @@ class TestAppend(unittest.TestCase):
             self.assertEqual(ET.tostring(jp2.box[-1].xml.getroot()),
                              b'<data>0</data>')
 
-    def test_only_xml_allowed_to_append(self):
+    def test_append_allowable_boxes(self):
         """Only XML boxes are allowed to be appended."""
         with tempfile.NamedTemporaryFile(suffix=".jp2") as tfile:
             shutil.copyfile(self.jp2file, tfile.name)
 
             jp2 = Jp2k(tfile.name)
 
-            # Make a UUID box.
+            # Make a UUID box.  Only XMP UUID boxes can currently be appended.
             uuid_instance = uuid.UUID('00000000-0000-0000-0000-000000000000')
             data = b'0123456789'
             uuidbox = glymur.jp2box.UUIDBox(uuid_instance, data)
diff --git a/setup.py b/setup.py
index 89e69f7..b780e4d 100644
--- a/setup.py
+++ b/setup.py
@@ -42,7 +42,7 @@ kwargs['classifiers'] = clssfrs
 
 # Get the version string.  Cannot do this by importing glymur!
 version_file = os.path.join('glymur', 'version.py')
-with open('glymur/version.py', 'rt') as fptr:
+with open(version_file, 'rt') as fptr:
     contents = fptr.read()
     match = re.search('version\s*=\s*"(?P<version>\d*.\d*.\d*.*)"\n', contents)
     kwargs['version'] = match.group('version')