diff --git a/script/RobotTCP.py b/script/RobotTCP.py
index 5204a46..642dd6b 100644
--- a/script/RobotTCP.py
+++ b/script/RobotTCP.py
@@ -220,7 +220,7 @@ class RobotTCP(TcpDevice, Stoppable):
         return self.eval_int("getMoveId()")
 
     def set_move_id(self, id):
-        return self.evaluate("setMoveId(" + id + " )")
+        return self.evaluate("setMoveId(" + str(id) + " )")
 
     def get_joint_forces(self):
         robot_tcp.evaluate("getJointForce(arr)")