diff --git a/conf/flight_plans/rotorcraft_basic.xml b/conf/flight_plans/rotorcraft_basic.xml
index 33b839bbcf..31c0d43489 100644
--- a/conf/flight_plans/rotorcraft_basic.xml
+++ b/conf/flight_plans/rotorcraft_basic.xml
@@ -34,7 +34,7 @@
       <attitude pitch="0" roll="0" throttle="0" vmode="throttle" until="FALSE"/>
     </block>
     <block name="Takeoff" strip_button="Takeoff" strip_icon="takeoff.png">
-      <exception cond="stateGetPositionEnu_f()->z > 2.0" deroute="Standby"/>
+      <exception cond="stateGetPositionEnu_f() @DEREF z @GT 2.0" deroute="Standby"/>
       <call_once fun="NavSetWaypointHere(WP_CLIMB)"/>
       <stay vmode="climb" climb="nav_climb_vspeed" wp="CLIMB"/>
     </block>
diff --git a/sw/lib/ocaml/expr_lexer.mll b/sw/lib/ocaml/expr_lexer.mll
index a4a40e45fd..2ff45bb1ca 100644
--- a/sw/lib/ocaml/expr_lexer.mll
+++ b/sw/lib/ocaml/expr_lexer.mll
@@ -42,6 +42,7 @@ rule token = parse
   | '[' { LB }
   | ']' { RB }
   | "->" { DEREF }
+  | "@DEREF" {DEREF}
   | "==" { EQ }
   | "&&" { AND }
   | "@AND" { AND }