diff --git a/robotgame/worldobject.py b/robotgame/worldobject.py
index f0b2fd2..35bde80 100644
--- a/robotgame/worldobject.py
+++ b/robotgame/worldobject.py
@@ -73,7 +73,7 @@ class WorldObject(object):
             if self.holding:
                 self.holding.move(move_x, move_y)
 
-    def use(self):
+    def use(self, obj):
         pass
 
     def activate(self, setting):