diff --git a/glymur/jp2box.py b/glymur/jp2box.py
index d5e79e1..a599f84 100644
--- a/glymur/jp2box.py
+++ b/glymur/jp2box.py
@@ -2286,6 +2286,14 @@ class LabelBox(Jp2kBox):
         msg = 'glymur.jp2box.LabelBox("{0}")'.format(self.label)
         return msg
 
+    def write(self, fptr):
+        """Write a Label box to file.
+        """
+        length = 8 + len(self.label.encode())
+        fptr.write(struct.pack('>I', length))
+        fptr.write(self.box_id.encode())
+        fptr.write(self.label.encode())
+
     @staticmethod
     def parse(fptr, offset, length):
         """Parse Label box.
diff --git a/glymur/jp2k.py b/glymur/jp2k.py
index d159fcc..96b6e68 100644
--- a/glymur/jp2k.py
+++ b/glymur/jp2k.py
@@ -1119,6 +1119,7 @@ def _validate_jp2_box_sequence(boxes):
     _validate_jp2h(boxes)
     _validate_jp2c(boxes)
     _validate_association(boxes)
+    _validate_label(boxes)
     _validate_jpx_brand(boxes, boxes[1].brand)
     _validate_jpx_compatibility(boxes, boxes[1].compatibility_list)
     _validate_singletons(boxes)
@@ -1304,6 +1305,21 @@ def _validate_jpx_compatibility(boxes, compatibility_list):
             # Same set of checks on any child boxes.
             _validate_jpx_compatibility(box.box, compatibility_list)
 
+def _validate_label(boxes):
+    """
+    Label boxes can only be inside association, codestream headers, or
+    compositing layer header boxes.
+    """
+    for box in boxes:
+        if box.box_id != 'asoc':
+            if hasattr(box, 'box'):
+                for boxi in box.box:
+                    if boxi.box_id == 'lbl ':
+                        msg = "A label box cannot be nested inside a {0} box."
+                        msg = msg.format(box.box_id)
+                        raise IOError(msg)
+                # Same set of checks on any child boxes.
+                _validate_label(box.box)
 
 def _validate_association(boxes):
     """
diff --git a/glymur/test/test_jp2box_jpx.py b/glymur/test/test_jp2box_jpx.py
index 2ebeb1f..8b5e075 100644
--- a/glymur/test/test_jp2box_jpx.py
+++ b/glymur/test/test_jp2box_jpx.py
@@ -67,8 +67,8 @@ class TestJPXWrap(unittest.TestCase):
             self.assertEqual(ET.tostring(jpx.box[-1].box[1].xml.getroot()),
                              b'<data>0</data>')
 
-    def test_association_box(self):
-        """Wrap JP2 to JPX with asoc(nlst, xml)"""
+    def test_association_label_box(self):
+        """Wrap JP2 to JPX with asoc, label, and nlst boxes"""
         jp2 = Jp2k(self.jp2file)
         boxes = [jp2.box[idx] for idx in [0, 1, 2, 4]]
 
@@ -76,11 +76,13 @@ class TestJPXWrap(unittest.TestCase):
         boxes[1].brand = 'jpx '
         boxes[1].compatibility_list = ['jp2 ', 'jpx ']
 
+        label = 'this is a test'
+        lblb = glymur.jp2box.LabelBox(label)
         numbers = (0, 1)
         nlst = glymur.jp2box.NumberListBox(numbers)
         the_xml = ET.fromstring('<?xml version="1.0"?><data>0</data>')
         xmlb = glymur.jp2box.XMLBox(xml=the_xml)
-        asoc = glymur.jp2box.AssociationBox([nlst, xmlb])
+        asoc = glymur.jp2box.AssociationBox([nlst, xmlb, lblb])
         boxes.append(asoc)
 
         with tempfile.NamedTemporaryFile(suffix=".jpx") as tfile:
@@ -89,10 +91,12 @@ class TestJPXWrap(unittest.TestCase):
             self.assertEqual(jpx.box[1].compatibility_list, ['jp2 ', 'jpx '])
             self.assertEqual(jpx.box[-1].box_id, 'asoc')
             self.assertEqual(jpx.box[-1].box[0].box_id, 'nlst')
-            self.assertEqual(jpx.box[-1].box[1].box_id, 'xml ')
             self.assertEqual(jpx.box[-1].box[0].associations, numbers)
+            self.assertEqual(jpx.box[-1].box[1].box_id, 'xml ')
             self.assertEqual(ET.tostring(jpx.box[-1].box[1].xml.getroot()),
                              b'<data>0</data>')
+            self.assertEqual(jpx.box[-1].box[2].box_id, 'lbl ')
+            self.assertEqual(jpx.box[-1].box[2].label, label)
 
     def test_only_one_data_reference(self):
         """Data reference boxes cannot be inside a superbox ."""
@@ -111,6 +115,23 @@ class TestJPXWrap(unittest.TestCase):
             with self.assertRaises(IOError):
                 jpx = jp2.wrap(tfile.name, boxes=boxes)
 
+    def test_lbl_at_top_level(self):
+        """Label boxes can only be inside a asoc box ."""
+        jp2 = Jp2k(self.jp2file)
+        boxes = [jp2.box[idx] for idx in [0, 1, 2, 4]]
+
+        flag = 0
+        version = (0, 0, 0)
+        url = 'file:////usr/local/bin'
+        lblb = glymur.jp2box.LabelBox('hi there')
+
+        # Put it inside the jp2 header box.
+        boxes[2].box.append(lblb)
+
+        with tempfile.NamedTemporaryFile(suffix=".jpx") as tfile:
+            with self.assertRaises(IOError):
+                jpx = jp2.wrap(tfile.name, boxes=boxes)
+
     def test_data_reference_not_at_top_level(self):
         """Data reference boxes cannot be inside a superbox ."""
         jp2 = Jp2k(self.jp2file)