diff --git a/kmljoin.py b/kmljoin.py
index bc8f20602863cc93d8acb8834c4a80625f677b13..ad087b50b41292fdfff953681d3ff42ae8fb6cc0 100755
--- a/kmljoin.py
+++ b/kmljoin.py
@@ -1,10 +1,6 @@
 #!/bin/env python3
 """kmljoin - Join multiple KML files into a single KML file."""
 
-# Missing features:
-#  - Warn about large temporal discontinuity between files
-#  - Combine distinct airports/waypoint names for title
-
 
 import copy
 import sys
@@ -16,8 +12,8 @@ XML_NS = {
     'gx': 'http://www.google.com/kml/ext/2.2',
 }
 
-ET.register_namespace('', 'http://www.opengis.net/kml/2.2')
-ET.register_namespace('gx', 'http://www.google.com/kml/ext/2.2')
+for nskey, ns in XML_NS.items():
+    ET.register_namespace(nskey, ns)
 
 def combine_files(kml_files):
     """Combine two or more KML files into one."""