diff --git a/src/SimulationRunner.cc b/src/SimulationRunner.cc
index 03fb30ba3f..a6a61f288b 100644
--- a/src/SimulationRunner.cc
+++ b/src/SimulationRunner.cc
@@ -100,7 +100,14 @@ SimulationRunner::SimulationRunner(const sdf::World &_world,
   : sdfWorld(_world), serverConfig(_config)
 {
   // Keep world name
-  this->worldName = _world.Name();
+  this->worldName = transport::TopicUtils::AsValidTopic(_world.Name());
+
+  if (this->worldName.empty())
+  {
+    gzerr << "Can't start simulation runner with this world name ["
+          << _world.Name() << "]." << std::endl;
+    return;
+  }
 
   this->parametersRegistry = std::make_unique<
     gz::transport::parameters::ParametersRegistry>(
diff --git a/src/systems/ackermann_steering/AckermannSteering.cc b/src/systems/ackermann_steering/AckermannSteering.cc
index 59d81052f8..f1398c6c95 100644
--- a/src/systems/ackermann_steering/AckermannSteering.cc
+++ b/src/systems/ackermann_steering/AckermannSteering.cc
@@ -677,6 +677,11 @@ void AckermannSteering::PostUpdate(const UpdateInfo &_info,
   // Nothing left to do if paused.
   if (_info.paused)
     return;
+
+  if (this->dataPtr->leftSteeringJoints.empty() ||
+      this->dataPtr->rightSteeringJoints.empty())
+    return;
+
   if (this->dataPtr->steeringOnly)
   {
     this->dataPtr->UpdateAngle(_info, _ecm);