diff --git a/launch/online_async_launch.py b/launch/online_async_launch.py
index 0bebe4a99..2fd82c819 100644
--- a/launch/online_async_launch.py
+++ b/launch/online_async_launch.py
@@ -1,3 +1,5 @@
+import os
+
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument
 from launch.substitutions import LaunchConfiguration
@@ -7,15 +9,21 @@
 
 def generate_launch_description():
     use_sim_time = LaunchConfiguration('use_sim_time')
+    params_file = LaunchConfiguration('params_file')
 
     declare_use_sim_time_argument = DeclareLaunchArgument(
         'use_sim_time',
         default_value='true',
         description='Use simulation/Gazebo clock')
+    declare_params_file_cmd = DeclareLaunchArgument(
+        'params_file',
+        default_value=os.path.join(get_package_share_directory("slam_toolbox"),
+                                   'config', 'mapper_params_online_async.yaml'),
+        description='Full path to the ROS2 parameters file to use for the slam_toolbox node')
 
     start_async_slam_toolbox_node = Node(
         parameters=[
-          get_package_share_directory("slam_toolbox") + '/config/mapper_params_online_async.yaml',
+          params_file,
           {'use_sim_time': use_sim_time}
         ],
         package='slam_toolbox',
@@ -26,6 +34,7 @@ def generate_launch_description():
     ld = LaunchDescription()
 
     ld.add_action(declare_use_sim_time_argument)
+    ld.add_action(declare_params_file_cmd)
     ld.add_action(start_async_slam_toolbox_node)
 
     return ld
diff --git a/launch/online_sync_launch.py b/launch/online_sync_launch.py
index ae38653da..ca1694e7d 100644
--- a/launch/online_sync_launch.py
+++ b/launch/online_sync_launch.py
@@ -1,3 +1,5 @@
+import os
+
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument
 from launch.substitutions import LaunchConfiguration
@@ -7,15 +9,21 @@
 
 def generate_launch_description():
     use_sim_time = LaunchConfiguration('use_sim_time')
+    params_file = LaunchConfiguration('params_file')
 
     declare_use_sim_time_argument = DeclareLaunchArgument(
         'use_sim_time',
         default_value='true',
         description='Use simulation/Gazebo clock')
+    declare_params_file_cmd = DeclareLaunchArgument(
+        'params_file',
+        default_value=os.path.join(get_package_share_directory("slam_toolbox"),
+                                   'config', 'mapper_params_online_sync.yaml'),
+        description='Full path to the ROS2 parameters file to use for the slam_toolbox node')
 
     start_sync_slam_toolbox_node = Node(
         parameters=[
-          get_package_share_directory("slam_toolbox") + '/config/mapper_params_online_sync.yaml',
+          params_file,
           {'use_sim_time': use_sim_time}
         ],
         package='slam_toolbox',
@@ -26,6 +34,7 @@ def generate_launch_description():
     ld = LaunchDescription()
 
     ld.add_action(declare_use_sim_time_argument)
+    ld.add_action(declare_params_file_cmd)
     ld.add_action(start_sync_slam_toolbox_node)
 
     return ld