diff --git a/conf/flight_plans/flight_plan.dtd b/conf/flight_plans/flight_plan.dtd
index 5abc3931eb..25720efcc4 100644
--- a/conf/flight_plans/flight_plan.dtd
+++ b/conf/flight_plans/flight_plan.dtd
@@ -184,8 +184,11 @@ until CDATA #IMPLIED>
 <!ATTLIST eight
 center CDATA #REQUIRED
 turn_around CDATA #REQUIRED
+alt CDATA #IMPLIED
+until CDATA #IMPLIED
 radius CDATA #REQUIRED>
 
+
 <!ATTLIST oval
 p1 CDATA #REQUIRED
 p2 CDATA #REQUIRED
@@ -193,6 +196,7 @@ vmode CDATA #IMPLIED
 pitch CDATA #IMPLIED
 throttle CDATA #IMPLIED
 radius CDATA #REQUIRED
+alt CDATA #IMPLIED
 until CDATA #IMPLIED>
 
 <!ATTLIST survey_rectangle