diff --git a/source/cyclusagent.py b/source/cyclusagent.py
index b992f106..daeeb4a4 100644
--- a/source/cyclusagent.py
+++ b/source/cyclusagent.py
@@ -139,6 +139,9 @@ def prepare_type(cpptype, othertype):
     'package': None,
     'inpackage': None,
     'outpackage': None,
+    'transportunit': None,
+    'intransportunit': None,
+    'outtransportunit': None,
     'none': None,
     None: None,
     '': None,
@@ -156,6 +159,9 @@ def prepare_type(cpptype, othertype):
     'package': None,
     'inpackage': None,
     'outpackage': None,
+    'transportunit': None,
+    'intransportunit': None,
+    'outtransportunit': None,
     }
 
 def _type(cpp, given=None):