diff --git a/launch/tier4_perception_launch/launch/object_recognition/detection/camera_lidar_fusion_based_detection.launch.xml b/launch/tier4_perception_launch/launch/object_recognition/detection/camera_lidar_fusion_based_detection.launch.xml
index 10a53b7d4d718..2f9abbb99cec9 100644
--- a/launch/tier4_perception_launch/launch/object_recognition/detection/camera_lidar_fusion_based_detection.launch.xml
+++ b/launch/tier4_perception_launch/launch/object_recognition/detection/camera_lidar_fusion_based_detection.launch.xml
@@ -220,7 +220,7 @@
     <include file="$(find-pkg-share object_merger)/launch/object_association_merger.launch.xml">
       <arg name="input/object0" value="temporary_merged_objects"/>
       <arg name="input/object1" value="clustering/objects"/>
-      <arg name="output/object" value="($var merger/output/objects)"/>
+      <arg name="output/object" value="$(var merger/output/objects)"/>
     </include>
   </group>