diff --git a/Cantera/python/ctml_writer.py b/Cantera/python/ctml_writer.py
index 95d19bd9a..ed2a07892 100644
--- a/Cantera/python/ctml_writer.py
+++ b/Cantera/python/ctml_writer.py
@@ -1,4 +1,7 @@
 #!/usr/local/bin/python
+#
+#  $Id$
+#
 """
  Cantera .cti input file processor