diff --git a/diagnostic_aggregator/include/diagnostic_aggregator/aggregator.hpp b/diagnostic_aggregator/include/diagnostic_aggregator/aggregator.hpp
index 1d2c7e638..785c34118 100644
--- a/diagnostic_aggregator/include/diagnostic_aggregator/aggregator.hpp
+++ b/diagnostic_aggregator/include/diagnostic_aggregator/aggregator.hpp
@@ -39,6 +39,7 @@
 #ifndef DIAGNOSTIC_AGGREGATOR__AGGREGATOR_HPP_
 #define DIAGNOSTIC_AGGREGATOR__AGGREGATOR_HPP_
 
+#include <atomic>
 #include <map>
 #include <memory>
 #include <set>
@@ -140,8 +141,10 @@ class Aggregator
   rclcpp::Service<diagnostic_msgs::srv::AddDiagnostics>::SharedPtr add_srv_;
   /// DiagnosticArray, /diagnostics
   rclcpp::Subscription<diagnostic_msgs::msg::DiagnosticArray>::SharedPtr diag_sub_;
-  /// ParameterEvent, /parameter_events
-  rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr param_sub_;
+  /// On-set parameters callback (node-scoped, no filtering needed)
+  rclcpp::node_interfaces::OnSetParametersCallbackHandle::SharedPtr param_cb_handle_;
+  /// Flag set by onParametersSet, consumed by publishData on the next cycle
+  std::atomic<bool> reinit_needed_{false};
   /// DiagnosticArray, /diagnostics_agg
   rclcpp::Publisher<diagnostic_msgs::msg::DiagnosticArray>::SharedPtr agg_pub_;
   /// DiagnosticStatus, /diagnostics_toplevel_state
@@ -174,10 +177,12 @@ class Aggregator
   /// Records all ROS warnings. No warnings are repeated.
   std::set<std::string> ros_warnings_;
 
-  /*
-   *!\brief Checks for new parameters to trigger reinitialization of the AnalyzerGroup and OtherAnalyzer
+  /*!
+   *\brief Validates incoming parameter changes and schedules reinitialization
+   * when new parameters are detected. Only fires for this node's own parameters.
    */
-  void parameterCallback(const rcl_interfaces::msg::ParameterEvent::SharedPtr param_msg);
+  rcl_interfaces::msg::SetParametersResult onParametersSet(
+    const std::vector<rclcpp::Parameter> & parameters);
 
   /*
    *!\brief (re)initializes the AnalyzerGroup and OtherAnalyzer
diff --git a/diagnostic_aggregator/src/aggregator.cpp b/diagnostic_aggregator/src/aggregator.cpp
index 6b60eee32..5ae840035 100644
--- a/diagnostic_aggregator/src/aggregator.cpp
+++ b/diagnostic_aggregator/src/aggregator.cpp
@@ -87,18 +87,25 @@ Aggregator::Aggregator(rclcpp::NodeOptions options)
     std::chrono::milliseconds(publish_rate_ms),
     std::bind(&Aggregator::publishData, this));
 
-  param_sub_ = n_->create_subscription<rcl_interfaces::msg::ParameterEvent>(
-    "/parameter_events", 1, std::bind(&Aggregator::parameterCallback, this, _1));
+  param_cb_handle_ = n_->add_on_set_parameters_callback(
+    std::bind(&Aggregator::onParametersSet, this, _1));
 }
 
-void Aggregator::parameterCallback(const rcl_interfaces::msg::ParameterEvent::SharedPtr msg)
+rcl_interfaces::msg::SetParametersResult Aggregator::onParametersSet(
+  const std::vector<rclcpp::Parameter> & parameters)
 {
-  if (msg->node == "/" + std::string(n_->get_name())) {
-    if (msg->new_parameters.size() != 0) {
-      base_path_ = "";
-      initAnalyzers();
+  // Check if any of the incoming parameters are new. If so, flag for reinitialization.
+  // The method publishData() will pick it up on the next publish cycle and call initAnalyzers().
+  for (const auto & p : parameters) {
+    if (!n_->has_parameter(p.get_name())) {
+      reinit_needed_.store(true);
+      break;
     }
   }
+
+  rcl_interfaces::msg::SetParametersResult result;
+  result.successful = true;
+  return result;
 }
 
 void Aggregator::initAnalyzers()
@@ -211,6 +218,13 @@ Aggregator::~Aggregator()
 void Aggregator::publishData()
 {
   RCLCPP_DEBUG(logger_, "publishData()");
+
+  // Check if reinitialization is needed because new parameters have been set.
+  if (reinit_needed_.exchange(false)) {
+    base_path_ = "";
+    initAnalyzers();
+  }
+
   DiagnosticArray diag_array;
   DiagnosticStatus diag_toplevel_state;
   diag_toplevel_state.name = "toplevel_state";