diff --git a/ros2_control_demo_description/diffbot/urdf/diffbot_description.urdf.xacro b/ros2_control_demo_description/diffbot/urdf/diffbot_description.urdf.xacro
index 263be605..a5be5c6a 100644
--- a/ros2_control_demo_description/diffbot/urdf/diffbot_description.urdf.xacro
+++ b/ros2_control_demo_description/diffbot/urdf/diffbot_description.urdf.xacro
@@ -49,6 +49,7 @@
+
@@ -84,6 +85,7 @@
+
diff --git a/ros2_control_demo_description/rrbot/urdf/rrbot_description.urdf.xacro b/ros2_control_demo_description/rrbot/urdf/rrbot_description.urdf.xacro
index a86af5c6..4017ab63 100644
--- a/ros2_control_demo_description/rrbot/urdf/rrbot_description.urdf.xacro
+++ b/ros2_control_demo_description/rrbot/urdf/rrbot_description.urdf.xacro
@@ -50,6 +50,7 @@
+
@@ -85,6 +86,7 @@
+