diff --git a/ontology/update.py b/ontology/update.py
index 5b8aa64..b0acdab 100755
--- a/ontology/update.py
+++ b/ontology/update.py
@@ -51,6 +51,9 @@ if __name__ == '__main__':
                 p = p[part]
             p[child] = {}
         else:
+            if parent not in tree['missing']:
+                tree['missing'][parent] = {}
+            tree['missing'][parent][child] = {}
             print('missing root - %s: %s' % (parent, child))
 
     #print(json.dumps(tree, indent=4, sort_keys=True))