diff --git a/object_tf_service.py b/object_tf_service.py
index 5a68af6..f9b51e2 100755
--- a/object_tf_service.py
+++ b/object_tf_service.py
@@ -40,7 +40,7 @@ class tf_service():
 
 	def gazebo_link_subscriber(self):
 		rospy.init_node('gazebo_link_subscriber')
-		rospy.Subscriber("/gazebo/link_states", LinkStates, callback)
+		rospy.Subscriber("/gazebo/link_states", LinkStates, self._callback)
 		# spin() simply keeps python from exiting until this node is stopped
 		rospy.spin()