diff --git a/src/rl_sar/CMakeLists.txt b/src/rl_sar/CMakeLists.txt
index 9a0c127..72cb6be 100644
--- a/src/rl_sar/CMakeLists.txt
+++ b/src/rl_sar/CMakeLists.txt
@@ -29,7 +29,8 @@ find_package(rclpy REQUIRED)
 find_package(gazebo_msgs REQUIRED)
 find_package(std_srvs REQUIRED)
 
-find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+# Make sure to find Python 3.8
+find_package(Python3 3.8 EXACT COMPONENTS Interpreter Development REQUIRED)
 
 link_directories(/usr/local/lib)
 include_directories(${YAML_CPP_INCLUDE_DIR})
diff --git a/src/rl_sar/scripts/rl_sim.py b/src/rl_sar/scripts/rl_sim.py
index 5e0d482..7a85841 100755
--- a/src/rl_sar/scripts/rl_sim.py
+++ b/src/rl_sar/scripts/rl_sim.py
@@ -54,7 +54,7 @@ class RL_Sim(RL, Node):
         self.ReadYaml(self.robot_name)
         for i in range(len(self.params.observations)):
             if self.params.observations[i] == "ang_vel":
-                self.params.observations[i] = "ang_vel_world"
+                self.params.observations[i] = "ang_vel_body"
 
         # init rl
         torch.set_grad_enabled(False)
diff --git a/src/rl_sar/src/rl_sim.cpp b/src/rl_sar/src/rl_sim.cpp
index d60ea93..4030741 100644
--- a/src/rl_sar/src/rl_sim.cpp
+++ b/src/rl_sar/src/rl_sim.cpp
@@ -49,10 +49,9 @@ RL_Sim::RL_Sim()
     this->ReadYaml(this->robot_name);
     for (std::string &observation : this->params.observations)
     {
-        // In Gazebo, the coordinate system for angular velocity is in the world coordinate system.
         if (observation == "ang_vel")
         {
-            observation = "ang_vel_world";
+            observation = "ang_vel_body";
         }
     }