diff --git a/preferences.xml b/preferences.xml
index 8cd338604..0c4debbd9 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -597,7 +597,9 @@ Started September 2000 by David Megginson, david@megginson.com
   <traffic-manager>
      <enabled type="bool">true</enabled>
      <heuristics type="bool">true</heuristics>
+     <datafile type="string"></datafile>
      <instantaneous-action type="bool">false</instantaneous-action>
+     <dumpdata type="bool">false</dumpdata>
      <proportion>1.0</proportion>
   </traffic-manager>