diff --git a/PathPlanning/RRTStarDubins/rrt_star_dubins.py b/PathPlanning/RRTStarDubins/rrt_star_dubins.py
index 4728cbd7..fdc659e6 100644
--- a/PathPlanning/RRTStarDubins/rrt_star_dubins.py
+++ b/PathPlanning/RRTStarDubins/rrt_star_dubins.py
@@ -66,6 +66,10 @@ class RRT():
         # generate coruse
         lastIndex = self.get_best_last_index()
         #  print(lastIndex)
+
+        if lastIndex is None:
+            return None
+
         path = self.gen_final_course(lastIndex)
         return path