diff --git a/example_12/controllers/src/passthrough_controller.cpp b/example_12/controllers/src/passthrough_controller.cpp
index 92660438a..345bf9b6f 100644
--- a/example_12/controllers/src/passthrough_controller.cpp
+++ b/example_12/controllers/src/passthrough_controller.cpp
@@ -85,6 +85,11 @@ controller_interface::CallbackReturn PassthroughController::on_configure(
   reference_interfaces_.resize(
     reference_interface_names_.size(), std::numeric_limits<double>::quiet_NaN());
 
+  for (size_t i = 0; i < reference_interface_names_.size(); i++)
+  {
+    REGISTER_ROS2_CONTROL_INTROSPECTION(reference_interface_names_[i], &reference_interfaces_[i]);
+  }
+
   return controller_interface::CallbackReturn::SUCCESS;
 }
 
diff --git a/example_12/hardware/rrbot.cpp b/example_12/hardware/rrbot.cpp
index a6cc4cf77..cba7968bd 100644
--- a/example_12/hardware/rrbot.cpp
+++ b/example_12/hardware/rrbot.cpp
@@ -81,6 +81,10 @@ hardware_interface::CallbackReturn RRBotSystemPositionOnlyHardware::on_init(
     }
   }
 
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_start_sec", &hw_start_sec_);
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_stop_sec", &hw_stop_sec_);
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_slowdown", &hw_slowdown_);
+
   return hardware_interface::CallbackReturn::SUCCESS;
 }
 
diff --git a/example_4/hardware/rrbot_system_with_sensor.cpp b/example_4/hardware/rrbot_system_with_sensor.cpp
index f211bb970..928ceb9a2 100644
--- a/example_4/hardware/rrbot_system_with_sensor.cpp
+++ b/example_4/hardware/rrbot_system_with_sensor.cpp
@@ -85,6 +85,11 @@ hardware_interface::CallbackReturn RRBotSystemWithSensorHardware::on_init(
     }
   }
 
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_start_sec", &hw_start_sec_);
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_stop_sec", &hw_stop_sec_);
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_slowdown", &hw_slowdown_);
+  REGISTER_ROS2_CONTROL_INTROSPECTION("hw_sensor_change", &hw_sensor_change_);
+
   return hardware_interface::CallbackReturn::SUCCESS;
 }