diff --git a/game/missiongenerator/aircraft/waypoints/racetrack.py b/game/missiongenerator/aircraft/waypoints/racetrack.py
index 03d35102..b167653c 100644
--- a/game/missiongenerator/aircraft/waypoints/racetrack.py
+++ b/game/missiongenerator/aircraft/waypoints/racetrack.py
@@ -72,7 +72,7 @@ class RaceTrackBuilder(PydcsWaypointBuilder):
 
         racetrack = ControlledTask(orbit)
         self.set_waypoint_tot(waypoint, flight_plan.patrol_start_time)
-        elapsed = int(flight_plan.patrol_duration.total_seconds())
+        elapsed = int((flight_plan.patrol_end_time - self.now).total_seconds())
         racetrack.stop_after_time(elapsed)
         # What follows is some code to cope with the broken 'stop after time' condition
         create_stop_orbit_trigger(racetrack, self.package, self.mission, elapsed)