diff --git a/src/modules/navigator/mission_feasibility_checker.cpp b/src/modules/navigator/mission_feasibility_checker.cpp
index e43eb4b475..af7b6736ab 100644
--- a/src/modules/navigator/mission_feasibility_checker.cpp
+++ b/src/modules/navigator/mission_feasibility_checker.cpp
@@ -58,6 +58,11 @@ MissionFeasibilityChecker::checkMissionFeasible(const mission_s &mission,
 		float max_distance_to_1st_waypoint, float max_distance_between_waypoints,
 		bool land_start_req)
 {
+	// trivial case: A mission with length zero cannot be valid
+	if ((int)mission.count <= 0) {
+		return false;
+	}
+
 	bool failed = false;
 	bool warned = false;