diff --git a/rmf_building_map_tools/building_map_generator/_init_argparse.py b/rmf_building_map_tools/building_map_generator/_init_argparse.py
index 783d57b0..5faf9d50 100644
--- a/rmf_building_map_tools/building_map_generator/_init_argparse.py
+++ b/rmf_building_map_tools/building_map_generator/_init_argparse.py
@@ -18,7 +18,7 @@
                            help="Path to output the map model files")
 shared_parser.add_argument("TEMPLATE_WORLD_FILE", type=str, default="",
                            help="Specify the template for"
-                           +" the base simulation.")
+                           + " the base simulation.")
 # Create subparsers for Gazebo and Nav generation
 gazebo_parser = subparsers.add_parser(
     'gazebo',