diff --git a/description/robot_core.xacro b/description/robot_core.xacro
index a1402df..feef0c4 100644
--- a/description/robot_core.xacro
+++ b/description/robot_core.xacro
@@ -109,7 +109,7 @@
     <joint name="left_wheel_joint" type="continuous">
         <parent link="chassis"/>
         <child link="left_wheel"/>
-        <origin xyz="${chassis_length/2 - 0.075} ${wheel_offset_y/2 + wheel_thickness/2 + 0.01} wheel_offset_z" rpy="-${pi/2} 0 0" />
+        <origin xyz="${chassis_length/2 - 0.075} ${wheel_offset_y/2 + wheel_thickness/2 + 0.01} ${wheel_offset_z}" rpy="-${pi/2} 0 0" />
         <axis xyz="0 0 1"/>
     </joint>
 
@@ -142,7 +142,7 @@
     <joint name="right_wheel_joint" type="continuous">
         <parent link="chassis"/>
         <child link="right_wheel"/>
-        <origin xyz="${chassis_length/2 - 0.075} -${wheel_offset_y/2 + wheel_thickness/2 + 0.01} wheel_offset_z" rpy="${pi/2} 0 0" />
+        <origin xyz="${chassis_length/2 - 0.075} -${wheel_offset_y/2 + wheel_thickness/2 + 0.01} ${wheel_offset_z}" rpy="${pi/2} 0 0" />
         <axis xyz="0 0 -1"/>
     </joint>