diff --git a/toid_bot_description/src/toid_bot_control.xacro b/toid_bot_description/src/toid_bot_control.xacro
index 286e4f4..d405c38 100644
--- a/toid_bot_description/src/toid_bot_control.xacro
+++ b/toid_bot_description/src/toid_bot_control.xacro
@@ -11,17 +11,19 @@
       </xacro:unless>
       <xacro:if value="${use_mock_hardware}">
         <hardware>
-          <plugin>mock_components/GenericSystem</plugin>
-          <param name="calculate_dynamics">true</param>
+          <plugin>mock_components/GenericSystem</plugin> 
+          <param name="calculate_dynamics">true</param> 
         </hardware>
       </xacro:if>
 
       <joint name="drivewhl_l_joint">
         <command_interface name="velocity"/>
+        <state_interface name="position"/>
       </joint>
 
       <joint name="drivewhl_r_joint">
         <command_interface name="velocity"/>
+        <state_interface name="position"/>
       </joint>
 
     </ros2_control>