diff --git a/preferences.xml b/preferences.xml
index bf1c75420..0d88027f0 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -432,6 +432,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <traffic-manager>
      <enabled type="bool">true</enabled>
+     <instantaneous-action type="bool">true</instantaneous-action>
   </traffic-manager>
 
   <ai>