diff --git a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle1.cc b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle1.cc
index 56ea6cb..ff3b2e0 100644
--- a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle1.cc
+++ b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle1.cc
@@ -88,4 +88,4 @@ private:
 };
 // Register this plugin with the simulator
 GZ_REGISTER_MODEL_PLUGIN(Obstacle1)
-}// namespace gazebo
+}  // namespace gazebo
diff --git a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle2.cc b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle2.cc
index 84050ab..014f04e 100644
--- a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle2.cc
+++ b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacle2.cc
@@ -104,4 +104,4 @@ private:
 };
 // Register this plugin with the simulator
 GZ_REGISTER_MODEL_PLUGIN(Obstacle2)
-}// namespace gazebo
+}  // namespace gazebo
diff --git a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacles.cc b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacles.cc
index 185766e..a1a444c 100644
--- a/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacles.cc
+++ b/turtlebot3_gazebo/models/turtlebot3_dqn_world/obstacle_plugin/obstacles.cc
@@ -70,4 +70,4 @@ private:
 };
 // Register this plugin with the simulator
 GZ_REGISTER_MODEL_PLUGIN(Obstacles)
-}// namespace gazebo
+}  // namespace gazebo