diff --git a/sciurus17_examples/launch/demo.launch.py b/sciurus17_examples/launch/demo.launch.py
index 20b4f6d..9b7cc99 100644
--- a/sciurus17_examples/launch/demo.launch.py
+++ b/sciurus17_examples/launch/demo.launch.py
@@ -19,6 +19,7 @@
 from launch.conditions import IfCondition
 from launch.launch_description_sources import PythonLaunchDescriptionSource
 from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import SetParameter
 
 
 def generate_launch_description():
@@ -30,6 +31,12 @@ def generate_launch_description():
         'use_chest_camera', default_value='true', description='Use chest camera.'
     )
 
+    declare_use_sim_time = DeclareLaunchArgument(
+        'use_sim_time',
+        default_value='false',
+        description=('Set true when using the simulator.'),
+    )
+
     move_group = IncludeLaunchDescription(
         PythonLaunchDescriptionSource(
             [
@@ -64,6 +71,8 @@ def generate_launch_description():
 
     return LaunchDescription(
         [
+            SetParameter(name='use_sim_time', value=LaunchConfiguration('use_sim_time')),
+            declare_use_sim_time,
             declare_use_head_camera,
             declare_use_chest_camera,
             move_group,