diff --git a/src/core/grabber/include/grabber/device_grabber.hpp b/src/core/grabber/include/grabber/device_grabber.hpp
index 4ed957796..7017e561c 100644
--- a/src/core/grabber/include/grabber/device_grabber.hpp
+++ b/src/core/grabber/include/grabber/device_grabber.hpp
@@ -470,7 +470,7 @@ class device_grabber final : public pqrs::dispatcher::extra::dispatcher_client {
 
           if (hid_manager_) {
             hid_manager_->async_set_device_matched_delay(
-                profile.get_parameters().get_delay_milliseconds_before_open_device());
+                profile.get_parameters()->get_delay_milliseconds_before_open_device());
             hid_manager_->async_start();
           }
 
diff --git a/src/lib/libkrbn/src/libkrbn_configuration.cpp b/src/lib/libkrbn/src/libkrbn_configuration.cpp
index aff85a81d..5d3535abf 100644
--- a/src/lib/libkrbn/src/libkrbn_configuration.cpp
+++ b/src/lib/libkrbn/src/libkrbn_configuration.cpp
@@ -213,13 +213,13 @@ void libkrbn_core_configuration_erase_profile(size_t index) {
 
 int libkrbn_core_configuration_get_selected_profile_parameters_delay_milliseconds_before_open_device(void) {
   auto c = get_current_core_configuration();
-  auto count = c->get_selected_profile().get_parameters().get_delay_milliseconds_before_open_device().count();
+  auto count = c->get_selected_profile().get_parameters()->get_delay_milliseconds_before_open_device().count();
   return static_cast<int>(count);
 }
 
 void libkrbn_core_configuration_set_selected_profile_parameters_delay_milliseconds_before_open_device(int value) {
   auto c = get_current_core_configuration();
-  c->get_selected_profile().get_parameters().set_delay_milliseconds_before_open_device(
+  c->get_selected_profile().get_parameters()->set_delay_milliseconds_before_open_device(
       std::chrono::milliseconds(value));
 }
 
diff --git a/src/share/core_configuration/configuration_json_helper.hpp b/src/share/core_configuration/configuration_json_helper.hpp
index 2a72b3ea1..60115b444 100644
--- a/src/share/core_configuration/configuration_json_helper.hpp
+++ b/src/share/core_configuration/configuration_json_helper.hpp
@@ -179,9 +179,16 @@ class object_t final : public base_t {
 
   void update_value(const nlohmann::json& json,
                     error_handling error_handling) override {
-    if (auto v = pqrs::json::find_object(json, key_)) {
-      value_ = std::make_shared<T>(v->value(),
+    auto it = json.find(key_);
+    if (it == std::end(json)) {
+      return;
+    }
+
+    try {
+      value_ = std::make_shared<T>(*it,
                                    error_handling);
+    } catch (pqrs::json::unmarshal_error& e) {
+      throw pqrs::json::unmarshal_error(fmt::format("`{0}` error: {1}", key_, e.what()));
     }
   }
 
diff --git a/src/share/core_configuration/details/global_configuration.hpp b/src/share/core_configuration/details/global_configuration.hpp
index 0a3d6a8e1..85f73bcc5 100644
--- a/src/share/core_configuration/details/global_configuration.hpp
+++ b/src/share/core_configuration/details/global_configuration.hpp
@@ -50,42 +50,42 @@ class global_configuration final {
     return j;
   }
 
-  bool get_check_for_updates_on_startup(void) const {
+  const bool& get_check_for_updates_on_startup(void) const {
     return check_for_updates_on_startup_;
   }
   void set_check_for_updates_on_startup(bool value) {
     check_for_updates_on_startup_ = value;
   }
 
-  bool get_show_in_menu_bar(void) const {
+  const bool& get_show_in_menu_bar(void) const {
     return show_in_menu_bar_;
   }
   void set_show_in_menu_bar(bool value) {
     show_in_menu_bar_ = value;
   }
 
-  bool get_show_profile_name_in_menu_bar(void) const {
+  const bool& get_show_profile_name_in_menu_bar(void) const {
     return show_profile_name_in_menu_bar_;
   }
   void set_show_profile_name_in_menu_bar(bool value) {
     show_profile_name_in_menu_bar_ = value;
   }
 
-  bool get_enable_notification_window(void) const {
+  const bool& get_enable_notification_window(void) const {
     return enable_notification_window_;
   }
   void set_enable_notification_window(bool value) {
     enable_notification_window_ = value;
   }
 
-  bool get_ask_for_confirmation_before_quitting(void) const {
+  const bool& get_ask_for_confirmation_before_quitting(void) const {
     return ask_for_confirmation_before_quitting_;
   }
   void set_ask_for_confirmation_before_quitting(bool value) {
     ask_for_confirmation_before_quitting_ = value;
   }
 
-  bool get_unsafe_ui(void) const {
+  const bool& get_unsafe_ui(void) const {
     return unsafe_ui_;
   }
   void set_unsafe_ui(bool value) {
diff --git a/src/share/core_configuration/details/machine_specific.hpp b/src/share/core_configuration/details/machine_specific.hpp
index 76d7563ae..7cb15fe61 100644
--- a/src/share/core_configuration/details/machine_specific.hpp
+++ b/src/share/core_configuration/details/machine_specific.hpp
@@ -33,7 +33,7 @@ class machine_specific final {
       return j;
     }
 
-    bool get_enable_multitouch_extension(void) const {
+    const bool& get_enable_multitouch_extension(void) const {
       return enable_multitouch_extension_;
     }
     void set_enable_multitouch_extension(bool value) {
diff --git a/src/share/core_configuration/details/profile.hpp b/src/share/core_configuration/details/profile.hpp
index d39dd3bb6..b91f18f5b 100644
--- a/src/share/core_configuration/details/profile.hpp
+++ b/src/share/core_configuration/details/profile.hpp
@@ -20,8 +20,12 @@ class profile final {
       : json_(json),
         error_handling_(error_handling),
         selected_(false),
+        parameters_(std::make_shared<details::parameters>()),
         simple_modifications_(std::make_shared<simple_modifications>()),
         fn_function_keys_(std::make_shared<simple_modifications>()) {
+    helper_values_.push_back_object<details::parameters>("parameters",
+                                                         parameters_);
+
     helper_values_.push_back_array<details::device>("devices",
                                                     devices_);
 
@@ -50,13 +54,6 @@ class profile final {
 
         selected_ = value.get<bool>();
 
-      } else if (key == "parameters") {
-        try {
-          parameters_ = value.get<parameters>();
-        } catch (const pqrs::json::unmarshal_error& e) {
-          throw pqrs::json::unmarshal_error(fmt::format("`{0}` error: {1}", key, e.what()));
-        }
-
       } else if (key == "simple_modifications") {
         try {
           simple_modifications_->update(value);
@@ -149,7 +146,6 @@ class profile final {
 
     j["name"] = name_;
     j["selected"] = selected_;
-    j["parameters"] = parameters_;
 
     {
       auto jj = simple_modifications_->to_json(nlohmann::json::array());
@@ -191,14 +187,10 @@ class profile final {
     selected_ = value;
   }
 
-  const details::parameters& get_parameters(void) const {
+  gsl::not_null<std::shared_ptr<details::parameters>> get_parameters(void) const {
     return parameters_;
   }
 
-  details::parameters& get_parameters(void) {
-    return const_cast<details::parameters&>(static_cast<const profile&>(*this).get_parameters());
-  }
-
   gsl::not_null<std::shared_ptr<simple_modifications>> get_simple_modifications(void) const {
     return simple_modifications_;
   }
@@ -273,7 +265,7 @@ class profile final {
   error_handling error_handling_;
   std::string name_;
   bool selected_;
-  details::parameters parameters_;
+  gsl::not_null<std::shared_ptr<details::parameters>> parameters_;
   gsl::not_null<std::shared_ptr<simple_modifications>> simple_modifications_;
   gsl::not_null<std::shared_ptr<simple_modifications>> fn_function_keys_;
   details::complex_modifications complex_modifications_;
diff --git a/src/share/core_configuration/details/profile/device.hpp b/src/share/core_configuration/details/profile/device.hpp
index 2347de533..81c231557 100644
--- a/src/share/core_configuration/details/profile/device.hpp
+++ b/src/share/core_configuration/details/profile/device.hpp
@@ -282,7 +282,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     return identifiers_;
   }
 
-  bool get_ignore(void) const {
+  const bool& get_ignore(void) const {
     return ignore_;
   }
   void set_ignore(bool value) {
@@ -291,7 +291,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_manipulate_caps_lock_led(void) const {
+  const bool& get_manipulate_caps_lock_led(void) const {
     return manipulate_caps_lock_led_;
   }
   void set_manipulate_caps_lock_led(bool value) {
@@ -300,7 +300,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_treat_as_built_in_keyboard(void) const {
+  const bool& get_treat_as_built_in_keyboard(void) const {
     return treat_as_built_in_keyboard_;
   }
   void set_treat_as_built_in_keyboard(bool value) {
@@ -309,7 +309,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_disable_built_in_keyboard_if_exists(void) const {
+  const bool& get_disable_built_in_keyboard_if_exists(void) const {
     return disable_built_in_keyboard_if_exists_;
   }
   void set_disable_built_in_keyboard_if_exists(bool value) {
@@ -318,7 +318,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_flip_x(void) const {
+  const bool& get_mouse_flip_x(void) const {
     return mouse_flip_x_;
   }
   void set_mouse_flip_x(bool value) {
@@ -327,7 +327,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_flip_y(void) const {
+  const bool& get_mouse_flip_y(void) const {
     return mouse_flip_y_;
   }
   void set_mouse_flip_y(bool value) {
@@ -336,7 +336,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_flip_vertical_wheel(void) const {
+  const bool& get_mouse_flip_vertical_wheel(void) const {
     return mouse_flip_vertical_wheel_;
   }
   void set_mouse_flip_vertical_wheel(bool value) {
@@ -345,7 +345,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_flip_horizontal_wheel(void) const {
+  const bool& get_mouse_flip_horizontal_wheel(void) const {
     return mouse_flip_horizontal_wheel_;
   }
   void set_mouse_flip_horizontal_wheel(bool value) {
@@ -354,7 +354,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_swap_xy(void) const {
+  const bool& get_mouse_swap_xy(void) const {
     return mouse_swap_xy_;
   }
   void set_mouse_swap_xy(bool value) {
@@ -363,7 +363,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_swap_wheels(void) const {
+  const bool& get_mouse_swap_wheels(void) const {
     return mouse_swap_wheels_;
   }
   void set_mouse_swap_wheels(bool value) {
@@ -372,7 +372,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_discard_x(void) const {
+  const bool& get_mouse_discard_x(void) const {
     return mouse_discard_x_;
   }
   void set_mouse_discard_x(bool value) {
@@ -381,7 +381,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_discard_y(void) const {
+  const bool& get_mouse_discard_y(void) const {
     return mouse_discard_y_;
   }
   void set_mouse_discard_y(bool value) {
@@ -390,7 +390,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_discard_vertical_wheel(void) const {
+  const bool& get_mouse_discard_vertical_wheel(void) const {
     return mouse_discard_vertical_wheel_;
   }
   void set_mouse_discard_vertical_wheel(bool value) {
@@ -399,7 +399,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_mouse_discard_horizontal_wheel(void) const {
+  const bool& get_mouse_discard_horizontal_wheel(void) const {
     return mouse_discard_horizontal_wheel_;
   }
   void set_mouse_discard_horizontal_wheel(bool value) {
@@ -408,7 +408,7 @@ if (abs(cos(radian)) <= abs(sin(radian))) {
     coordinate_between_properties();
   }
 
-  bool get_game_pad_swap_sticks(void) const {
+  const bool& get_game_pad_swap_sticks(void) const {
     return game_pad_swap_sticks_;
   }
   void set_game_pad_swap_sticks(bool value) {
diff --git a/src/share/core_configuration/details/profile/parameters.hpp b/src/share/core_configuration/details/profile/parameters.hpp
index 3a1a9d013..a2ad31f19 100644
--- a/src/share/core_configuration/details/profile/parameters.hpp
+++ b/src/share/core_configuration/details/profile/parameters.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "../../configuration_json_helper.hpp"
 #include "types.hpp"
 
 namespace krbn {
@@ -7,19 +8,34 @@ namespace core_configuration {
 namespace details {
 class parameters final {
 public:
-  parameters(void) : json_(nlohmann::json::object()),
-                     delay_milliseconds_before_open_device_(1000) {
+  parameters(const parameters&) = delete;
+
+  parameters(void)
+      : parameters(nlohmann::json::object(),
+                   krbn::core_configuration::error_handling::loose) {
   }
 
-  const nlohmann::json& get_json(void) const {
-    return json_;
+  parameters(const nlohmann::json& json,
+             error_handling error_handling)
+      : json_(json) {
+    helper_values_.push_back_value<std::chrono::milliseconds>("delay_milliseconds_before_open_device",
+                                                              delay_milliseconds_before_open_device_,
+                                                              std::chrono::milliseconds(1000));
+
+    pqrs::json::requires_object(json, "json");
+
+    helper_values_.update_value(json, error_handling);
   }
 
-  void set_json(const nlohmann::json& value) {
-    json_ = value;
+  nlohmann::json to_json(void) const {
+    auto j = json_;
+
+    helper_values_.update_json(j);
+
+    return j;
   }
 
-  std::chrono::milliseconds get_delay_milliseconds_before_open_device(void) const {
+  const std::chrono::milliseconds& get_delay_milliseconds_before_open_device(void) const {
     return delay_milliseconds_before_open_device_;
   }
 
@@ -34,30 +50,8 @@ class parameters final {
 private:
   nlohmann::json json_;
   std::chrono::milliseconds delay_milliseconds_before_open_device_;
+  configuration_json_helper::helper_values helper_values_;
 };
-
-inline void to_json(nlohmann::json& json, const parameters& value) {
-  json = value.get_json();
-  json["delay_milliseconds_before_open_device"] = value.get_delay_milliseconds_before_open_device().count();
-}
-
-inline void from_json(const nlohmann::json& json, parameters& value) {
-  pqrs::json::requires_object(json, "json");
-
-  for (const auto& [k, v] : json.items()) {
-    if (k == "delay_milliseconds_before_open_device") {
-      pqrs::json::requires_number(v, "`" + k + "`");
-
-      value.set_delay_milliseconds_before_open_device(std::chrono::milliseconds(v.get<int>()));
-
-    } else {
-      // Allow unknown keys in order to be able to load
-      // newer version of karabiner.json with older Karabiner-Elements.
-    }
-  }
-
-  value.set_json(json);
-}
 } // namespace details
 } // namespace core_configuration
 } // namespace krbn
diff --git a/tests/src/core_configuration/json/to_json_default.json b/tests/src/core_configuration/json/to_json_default.json
index af7d2e682..29a11aedc 100644
--- a/tests/src/core_configuration/json/to_json_default.json
+++ b/tests/src/core_configuration/json/to_json_default.json
@@ -12,9 +12,6 @@
                 }
             },
             "name": "Default profile",
-            "parameters": {
-                "delay_milliseconds_before_open_device": 1000
-            },
             "selected": true,
             "virtual_hid_keyboard": {
                 "country_code": 0,
diff --git a/tests/src/core_configuration/json/to_json_example.json b/tests/src/core_configuration/json/to_json_example.json
index 07baa10bd..af8459727 100644
--- a/tests/src/core_configuration/json/to_json_example.json
+++ b/tests/src/core_configuration/json/to_json_example.json
@@ -261,9 +261,6 @@
                 "rules": []
             },
             "name": "Empty",
-            "parameters": {
-                "delay_milliseconds_before_open_device": 1000
-            },
             "selected": false,
             "virtual_hid_keyboard": {
                 "country_code": 0,
@@ -295,9 +292,6 @@
                 }
             ],
             "name": "fn_function_keys v1",
-            "parameters": {
-                "delay_milliseconds_before_open_device": 1000
-            },
             "selected": false,
             "virtual_hid_keyboard": {
                 "country_code": 0,
@@ -317,9 +311,6 @@
                 "rules": []
             },
             "name": "simple_modifications v2",
-            "parameters": {
-                "delay_milliseconds_before_open_device": 1000
-            },
             "selected": false,
             "simple_modifications": [
                 {
diff --git a/tests/src/core_configuration/src/core_configuration_test.hpp b/tests/src/core_configuration/src/core_configuration_test.hpp
index f64061494..57bb3e839 100644
--- a/tests/src/core_configuration/src/core_configuration_test.hpp
+++ b/tests/src/core_configuration/src/core_configuration_test.hpp
@@ -685,9 +685,6 @@ void run_core_configuration_test(void) {
                                     })},
           {"name", ""},
           {"selected", false},
-          {"parameters", nlohmann::json::object({
-                             {"delay_milliseconds_before_open_device", 1000},
-                         })},
           {"virtual_hid_keyboard", get_default_virtual_hid_keyboard_json()},
       });
       expect(empty_profile.to_json() == expected) << UT_SHOW_LINE;
@@ -728,7 +725,7 @@ void run_core_configuration_test(void) {
       profile.set_name("profile 1");
       profile.set_selected(true);
 
-      profile.get_parameters().set_delay_milliseconds_before_open_device(std::chrono::milliseconds(500));
+      profile.get_parameters()->set_delay_milliseconds_before_open_device(std::chrono::milliseconds(500));
 
       profile.get_simple_modifications()->push_back_pair();
       // {
diff --git a/tests/src/core_configuration/src/errors_test.hpp b/tests/src/core_configuration/src/errors_test.hpp
index 0c231afdc..7eb0a50a3 100644
--- a/tests/src/core_configuration/src/errors_test.hpp
+++ b/tests/src/core_configuration/src/errors_test.hpp
@@ -14,7 +14,8 @@ void handle_json(const nlohmann::json& json) {
     krbn::core_configuration::details::device(json.at("input"),
                                               krbn::core_configuration::error_handling::strict);
   } else if (c == "parameters") {
-    json.at("input").get<krbn::core_configuration::details::parameters>();
+    krbn::core_configuration::details::parameters(json.at("input"),
+                                                  krbn::core_configuration::error_handling::strict);
   } else if (c == "profile") {
     krbn::core_configuration::details::profile(json.at("input"),
                                                krbn::core_configuration::error_handling::strict);