diff --git a/robomaster_pi/conn_vel.py b/robomaster_pi/conn_vel.py
index f4cbac344c6821d4db191a839b109ee163414e01..6b0a8c1d12bb044a4375e4056b1a1654ed20ea12 100644
--- a/robomaster_pi/conn_vel.py
+++ b/robomaster_pi/conn_vel.py
@@ -39,7 +39,7 @@ class vel_from_ros_node(Node):
             self.my_ep_chassis.drive_speed(x = 0, y = 0, z = 0.5)
 
 
-    def isConnected():
+    def isConnected(self):
         try:
             # connect to the host -- tells us if the host is actually
             # reachable