diff --git a/robotgame/boulder.py b/robotgame/boulder.py
index 8830fc2..8d7bed0 100644
--- a/robotgame/boulder.py
+++ b/robotgame/boulder.py
@@ -46,7 +46,7 @@ class Boulder(worldobject.WorldObject):
         self.ignore_list.append(player.Player)
 
     def fall(self, setting):
-        if setting:
+        if setting and not self.falling:
             self.frame = 0
             self.falling = True