diff --git a/lib/base/dictionary.cpp b/lib/base/dictionary.cpp
index 4fd9d24b9..435df3159 100644
--- a/lib/base/dictionary.cpp
+++ b/lib/base/dictionary.cpp
@@ -235,10 +235,10 @@ Object::Ptr Dictionary::Clone() const
 }
 
 /**
- * Returns an array containing all keys
+ * Returns an ordered vector containing all keys
  * which are currently set in this directory.
  *
- * @returns an array of key names
+ * @returns an ordered vector of key names
  */
 std::vector<String> Dictionary::GetKeys() const
 {
diff --git a/lib/icinga/command.ti b/lib/icinga/command.ti
index 5055ee3d5..a49d6e869 100644
--- a/lib/icinga/command.ti
+++ b/lib/icinga/command.ti
@@ -11,11 +11,11 @@ namespace icinga
 abstract class Command : CustomVarObject
 {
 	[config] Value command (CommandLine);
-	[config] Value arguments;
+	[config, signal_with_old_value] Value arguments;
 	[config] int timeout {
 		default {{{ return 60; }}}
 	};
-	[config] Dictionary::Ptr env;
+	[config, signal_with_old_value] Dictionary::Ptr env;
 	[config, required] Function::Ptr execute;
 };
 
diff --git a/lib/icinga/customvarobject.ti b/lib/icinga/customvarobject.ti
index 18da48b00..3e40f6680 100644
--- a/lib/icinga/customvarobject.ti
+++ b/lib/icinga/customvarobject.ti
@@ -9,7 +9,7 @@ namespace icinga
 
 abstract class CustomVarObject : ConfigObject
 {
-	[config] Dictionary::Ptr vars;
+	[config, signal_with_old_value] Dictionary::Ptr vars;
 };
 
 }
diff --git a/lib/icinga/host.ti b/lib/icinga/host.ti
index 1c8a6c9fe..d69d92102 100644
--- a/lib/icinga/host.ti
+++ b/lib/icinga/host.ti
@@ -15,7 +15,7 @@ class Host : Checkable
 	load_after Endpoint;
 	load_after Zone;
 
-	[config, no_user_modify, required] array(name(HostGroup)) groups {
+	[config, no_user_modify, required, signal_with_old_value] array(name(HostGroup)) groups {
 		default {{{ return new Array(); }}}
 	};
 
diff --git a/lib/icinga/notification.cpp b/lib/icinga/notification.cpp
index f1c2c9862..f3826ca81 100644
--- a/lib/icinga/notification.cpp
+++ b/lib/icinga/notification.cpp
@@ -133,6 +133,9 @@ void Notification::Start(bool runtimeCreated)
 	if (ApiListener::IsHACluster() && GetNextNotification() < Utility::GetTime() + 60)
 		SetNextNotification(Utility::GetTime() + 60, true);
 
+	for (const UserGroup::Ptr& group : GetUserGroups())
+		group->AddNotification(this);
+
 	ObjectImpl<Notification>::Start(runtimeCreated);
 }
 
@@ -144,6 +147,9 @@ void Notification::Stop(bool runtimeRemoved)
 
 	if (obj)
 		obj->UnregisterNotification(this);
+
+	for (const UserGroup::Ptr& group : GetUserGroups())
+		group->RemoveNotification(this);
 }
 
 Checkable::Ptr Notification::GetCheckable() const
diff --git a/lib/icinga/notification.ti b/lib/icinga/notification.ti
index e76a4f775..ab633c5dc 100644
--- a/lib/icinga/notification.ti
+++ b/lib/icinga/notification.ti
@@ -36,8 +36,8 @@ class Notification : CustomVarObject < NotificationNameComposer
 			return TimePeriod::GetByName(GetPeriodRaw());
 		}}}
 	};
-	[config, protected] array(name(User)) users (UsersRaw);
-	[config, protected] array(name(UserGroup)) user_groups (UserGroupsRaw);
+	[config, signal_with_old_value] array(name(User)) users (UsersRaw);
+	[config, signal_with_old_value] array(name(UserGroup)) user_groups (UserGroupsRaw);
 	[config] Dictionary::Ptr times;
 	[config] array(Value) types;
 	[no_user_view, no_user_modify] int type_filter_real (TypeFilter);
diff --git a/lib/icinga/service.ti b/lib/icinga/service.ti
index f76750ef4..4448c0aa8 100644
--- a/lib/icinga/service.ti
+++ b/lib/icinga/service.ti
@@ -27,7 +27,7 @@ class Service : Checkable < ServiceNameComposer
 	load_after Host;
 	load_after Zone;
 
-	[config, no_user_modify, required] array(name(ServiceGroup)) groups {
+	[config, no_user_modify, required, signal_with_old_value] array(name(ServiceGroup)) groups {
 		default {{{ return new Array(); }}}
 	};
 
diff --git a/lib/icinga/timeperiod.ti b/lib/icinga/timeperiod.ti
index ccfbcc3d4..58a5e8c4d 100644
--- a/lib/icinga/timeperiod.ti
+++ b/lib/icinga/timeperiod.ti
@@ -18,15 +18,15 @@ class TimePeriod : CustomVarObject
 				return m_DisplayName.m_Value;
 		}}}
 	};
-	[config] Dictionary::Ptr ranges;
+	[config, signal_with_old_value] Dictionary::Ptr ranges;
 	[config, required] Function::Ptr update;
 	[config] bool prefer_includes {
 		default {{{ return true; }}}
 	};
-	[config, required] array(name(TimePeriod)) excludes {
+	[config, required, signal_with_old_value] array(name(TimePeriod)) excludes {
 		default {{{ return new Array(); }}}
 	};
-	[config, required] array(name(TimePeriod)) includes {
+	[config, required, signal_with_old_value] array(name(TimePeriod)) includes {
 		default {{{ return new Array(); }}}
 	};
 	[state, no_user_modify] Value valid_begin;
diff --git a/lib/icinga/user.ti b/lib/icinga/user.ti
index 5de35b523..c69bac69c 100644
--- a/lib/icinga/user.ti
+++ b/lib/icinga/user.ti
@@ -19,7 +19,7 @@ class User : CustomVarObject
 				return m_DisplayName.m_Value;
 		}}}
 	};
-	[config, no_user_modify, required] array(name(UserGroup)) groups {
+	[config, no_user_modify, required, signal_with_old_value] array(name(UserGroup)) groups {
 		default {{{ return new Array(); }}}
 	};
 	[config, navigation] name(TimePeriod) period (PeriodRaw) {
diff --git a/lib/icinga/usergroup.cpp b/lib/icinga/usergroup.cpp
index 7702e337c..6ff4b89d4 100644
--- a/lib/icinga/usergroup.cpp
+++ b/lib/icinga/usergroup.cpp
@@ -76,6 +76,24 @@ void UserGroup::RemoveMember(const User::Ptr& user)
 	m_Members.erase(user);
 }
 
+std::set<Notification::Ptr> UserGroup::GetNotifications() const
+{
+	std::unique_lock<std::mutex> lock(m_UserGroupMutex);
+	return m_Notifications;
+}
+
+void UserGroup::AddNotification(const Notification::Ptr& notification)
+{
+	std::unique_lock<std::mutex> lock(m_UserGroupMutex);
+	m_Notifications.insert(notification);
+}
+
+void UserGroup::RemoveNotification(const Notification::Ptr& notification)
+{
+	std::unique_lock<std::mutex> lock(m_UserGroupMutex);
+	m_Notifications.erase(notification);
+}
+
 bool UserGroup::ResolveGroupMembership(const User::Ptr& user, bool add, int rstack) {
 
 	if (add && rstack > 20) {
diff --git a/lib/icinga/usergroup.hpp b/lib/icinga/usergroup.hpp
index e0325b4fc..c6f82a131 100644
--- a/lib/icinga/usergroup.hpp
+++ b/lib/icinga/usergroup.hpp
@@ -11,6 +11,7 @@ namespace icinga
 {
 
 class ConfigItem;
+class Notification;
 
 /**
  * An Icinga user group.
@@ -27,6 +28,10 @@ public:
 	void AddMember(const User::Ptr& user);
 	void RemoveMember(const User::Ptr& user);
 
+	std::set<intrusive_ptr<Notification>> GetNotifications() const;
+	void AddNotification(const intrusive_ptr<Notification>& notification);
+	void RemoveNotification(const intrusive_ptr<Notification>& notification);
+
 	bool ResolveGroupMembership(const User::Ptr& user, bool add = true, int rstack = 0);
 
 	static void EvaluateObjectRules(const User::Ptr& user);
@@ -34,6 +39,7 @@ public:
 private:
 	mutable std::mutex m_UserGroupMutex;
 	std::set<User::Ptr> m_Members;
+	std::set<intrusive_ptr<Notification>> m_Notifications;
 
 	static bool EvaluateObjectRule(const User::Ptr& user, const intrusive_ptr<ConfigItem>& group);
 };
diff --git a/lib/icingadb/icingadb-objects.cpp b/lib/icingadb/icingadb-objects.cpp
index ffcd46ac2..768095e2c 100644
--- a/lib/icingadb/icingadb-objects.cpp
+++ b/lib/icingadb/icingadb-objects.cpp
@@ -15,6 +15,7 @@
 #include "base/array.hpp"
 #include "base/exception.hpp"
 #include "base/utility.hpp"
+#include "base/object-packer.hpp"
 #include "icinga/command.hpp"
 #include "icinga/compatutility.hpp"
 #include "icinga/customvarobject.hpp"
@@ -35,6 +36,7 @@
 #include <mutex>
 #include <set>
 #include <utility>
+#include <type_traits>
 
 using namespace icinga;
 
@@ -127,6 +129,40 @@ void IcingaDB::ConfigStaticInitialize()
 	Service::OnHostProblemChanged.connect([](const Service::Ptr& service, const CheckResult::Ptr&, const MessageOrigin::Ptr&) {
 		IcingaDB::StateChangeHandler(service);
 	});
+
+	Notification::OnUsersRawChangedWithOldValue.connect([](const Notification::Ptr& notification, const Value& oldValues, const Value& newValues) {
+		IcingaDB::NotificationUsersChangedHandler(notification, oldValues, newValues);
+	});
+	Notification::OnUserGroupsRawChangedWithOldValue.connect([](const Notification::Ptr& notification, const Value& oldValues, const Value& newValues) {
+		IcingaDB::NotificationUserGroupsChangedHandler(notification, oldValues, newValues);
+	});
+	TimePeriod::OnRangesChangedWithOldValue.connect([](const TimePeriod::Ptr& timeperiod, const Value& oldValues, const Value& newValues) {
+		IcingaDB::TimePeriodRangesChangedHandler(timeperiod, oldValues, newValues);
+	});
+	TimePeriod::OnIncludesChangedWithOldValue.connect([](const TimePeriod::Ptr& timeperiod, const Value& oldValues, const Value& newValues) {
+		IcingaDB::TimePeriodIncludesChangedHandler(timeperiod, oldValues, newValues);
+	});
+	TimePeriod::OnExcludesChangedWithOldValue.connect([](const TimePeriod::Ptr& timeperiod, const Value& oldValues, const Value& newValues) {
+		IcingaDB::TimePeriodExcludesChangedHandler(timeperiod, oldValues, newValues);
+	});
+	User::OnGroupsChangedWithOldValue.connect([](const User::Ptr& user, const Value& oldValues, const Value& newValues) {
+		IcingaDB::UserGroupsChangedHandler(user, oldValues, newValues);
+	});
+	Host::OnGroupsChangedWithOldValue.connect([](const Host::Ptr& host, const Value& oldValues, const Value& newValues) {
+		IcingaDB::HostGroupsChangedHandler(host, oldValues, newValues);
+	});
+	Service::OnGroupsChangedWithOldValue.connect([](const Service::Ptr& service, const Value& oldValues, const Value& newValues) {
+		IcingaDB::ServiceGroupsChangedHandler(service, oldValues, newValues);
+	});
+	Command::OnEnvChangedWithOldValue.connect([](const ConfigObject::Ptr& command, const Value& oldValues, const Value& newValues) {
+		IcingaDB::CommandEnvChangedHandler(command, oldValues, newValues);
+	});
+	Command::OnArgumentsChangedWithOldValue.connect([](const ConfigObject::Ptr& command, const Value& oldValues, const Value& newValues) {
+		IcingaDB::CommandArgumentsChangedHandler(command, oldValues, newValues);
+	});
+	CustomVarObject::OnVarsChangedWithOldValue.connect([](const ConfigObject::Ptr& object, const Value& oldValues, const Value& newValues) {
+		IcingaDB::CustomVarsChangedHandler(object, oldValues, newValues);
+	});
 }
 
 void IcingaDB::UpdateAllConfigObjects()
@@ -609,7 +645,7 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 	CustomVarObject::Ptr customVarObject = dynamic_pointer_cast<CustomVarObject>(object);
 
 	if (customVarObject) {
-		auto vars(SerializeVars(customVarObject));
+		auto vars(SerializeVars(customVarObject->GetVars()));
 		if (vars) {
 			auto& typeCvs (hMSets[m_PrefixConfigObject + typeName + ":customvar"]);
 			auto& allCvs (hMSets[m_PrefixConfigObject + "customvar"]);
@@ -825,12 +861,7 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 
 	if (type == User::TypeInstance) {
 		User::Ptr user = static_pointer_cast<User>(object);
-
-		Array::Ptr groups;
-		ConfigObject::Ptr (*getGroup)(const String& name);
-
-		groups = user->GetGroups();
-		getGroup = &::GetObjectByName<UserGroup>;
+		Array::Ptr groups = user->GetGroups();
 
 		if (groups) {
 			ObjectLock groupsLock(groups);
@@ -839,9 +870,10 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 			groupIds->Reserve(groups->GetLength());
 
 			auto& members (hMSets[m_PrefixConfigObject + typeName + "group:member"]);
+			auto& notificationRecipients (hMSets[m_PrefixConfigObject + "notification:recipient"]);
 
 			for (auto& group : groups) {
-				auto groupObj ((*getGroup)(group));
+				UserGroup::Ptr groupObj = UserGroup::GetByName(group);
 				String groupId = GetObjectIdentifier(groupObj);
 				String id = HashValue(new Array({m_EnvironmentId, groupObj->GetName(), object->GetName()}));
 				members.emplace_back(id);
@@ -850,6 +882,16 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 
 				if (runtimeUpdate) {
 					AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + "group:member", data);
+
+					// Recipients are handled by notifications during initial dumps and only need to be handled here during runtime (e.g. User creation).
+					for (auto& notification : groupObj->GetNotifications()) {
+						String recipientId = HashValue(new Array({m_EnvironmentId, "usergroupuser", user->GetName(), groupObj->GetName(), notification->GetName()}));
+						notificationRecipients.emplace_back(recipientId);
+						Dictionary::Ptr recipientData = new Dictionary({{"notification_id", GetObjectIdentifier(notification)}, {"environment_id", m_EnvironmentId}, {"user_id", objectKey}, {"usergroup_id", groupId}});
+						notificationRecipients.emplace_back(JsonEncode(recipientData));
+
+						AddObjectDataToRuntimeUpdates(runtimeUpdates, recipientId, m_PrefixConfigObject + "notification:recipient", recipientData);
+					}
 				}
 
 				groupIds->Add(groupId);
@@ -863,10 +905,6 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 		Notification::Ptr notification = static_pointer_cast<Notification>(object);
 
 		std::set<User::Ptr> users = notification->GetUsers();
-
-		std::set<User::Ptr> allUsers;
-		std::copy(users.begin(), users.end(), std::inserter(allUsers, allUsers.begin()));
-
 		Array::Ptr userIds = new Array();
 
 		auto usergroups(notification->GetUserGroups());
@@ -875,16 +913,22 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 		userIds->Reserve(users.size());
 
 		auto& usrs (hMSets[m_PrefixConfigObject + typeName + ":user"]);
+		auto& notificationRecipients (hMSets[m_PrefixConfigObject + typeName + ":recipient"]);
 
 		for (auto& user : users) {
 			String userId = GetObjectIdentifier(user);
-			String id = HashValue(new Array({m_EnvironmentId, user->GetName(), object->GetName()}));
+			String id = HashValue(new Array({m_EnvironmentId, "user", user->GetName(), object->GetName()}));
 			usrs.emplace_back(id);
+			notificationRecipients.emplace_back(id);
+
 			Dictionary::Ptr data = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"user_id", userId}});
-			usrs.emplace_back(JsonEncode(data));
+			String dataJson = JsonEncode(data);
+			usrs.emplace_back(dataJson);
+			notificationRecipients.emplace_back(dataJson);
 
 			if (runtimeUpdate) {
 				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":user", data);
+				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":recipient", data);
 			}
 
 			userIds->Add(userId);
@@ -893,43 +937,38 @@ void IcingaDB::InsertObjectDependencies(const ConfigObject::Ptr& object, const S
 		usergroupIds->Reserve(usergroups.size());
 
 		auto& groups (hMSets[m_PrefixConfigObject + typeName + ":usergroup"]);
-		auto& notificationRecipients (hMSets[m_PrefixConfigObject + typeName + ":recipient"]);
 
 		for (auto& usergroup : usergroups) {
 			String usergroupId = GetObjectIdentifier(usergroup);
-
-			auto groupMembers = usergroup->GetMembers();
-			std::copy(groupMembers.begin(), groupMembers.end(), std::inserter(allUsers, allUsers.begin()));
-
 			String id = HashValue(new Array({m_EnvironmentId, "usergroup", usergroup->GetName(), object->GetName()}));
 			groups.emplace_back(id);
-			Dictionary::Ptr groupData = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"usergroup_id", usergroupId}});
-			groups.emplace_back(JsonEncode(groupData));
-
 			notificationRecipients.emplace_back(id);
-			Dictionary::Ptr notificationRecipientData = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"usergroup_id", usergroupId}});
-			notificationRecipients.emplace_back(JsonEncode(notificationRecipientData));
+
+			Dictionary::Ptr groupData = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"usergroup_id", usergroupId}});
+			String groupDataJson = JsonEncode(groupData);
+			groups.emplace_back(groupDataJson);
+			notificationRecipients.emplace_back(groupDataJson);
 
 			if (runtimeUpdate) {
 				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":usergroup", groupData);
-				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":recipient", notificationRecipientData);
+				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":recipient", groupData);
+			}
+
+			for (const User::Ptr& user : usergroup->GetMembers()) {
+				String userId = GetObjectIdentifier(user);
+				String recipientId = HashValue(new Array({m_EnvironmentId, "usergroupuser", user->GetName(), usergroup->GetName(), notification->GetName()}));
+				notificationRecipients.emplace_back(recipientId);
+				Dictionary::Ptr userData = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"user_id", userId}, {"usergroup_id", usergroupId}});
+				notificationRecipients.emplace_back(JsonEncode(userData));
+
+				if (runtimeUpdate) {
+					AddObjectDataToRuntimeUpdates(runtimeUpdates, recipientId, m_PrefixConfigObject + typeName + ":recipient", userData);
+				}
 			}
 
 			usergroupIds->Add(usergroupId);
 		}
 
-		for (auto& user : allUsers) {
-			String userId = GetObjectIdentifier(user);
-			String id = HashValue(new Array({m_EnvironmentId, "user", user->GetName(), object->GetName()}));
-			notificationRecipients.emplace_back(id);
-			Dictionary::Ptr data = new Dictionary({{"notification_id", objectKey}, {"environment_id", m_EnvironmentId}, {"user_id", userId}});
-			notificationRecipients.emplace_back(JsonEncode(data));
-
-			if (runtimeUpdate) {
-				AddObjectDataToRuntimeUpdates(runtimeUpdates, id, m_PrefixConfigObject + typeName + ":recipient", data);
-			}
-		}
-
 		return;
 	}
 
@@ -1121,10 +1160,11 @@ void IcingaDB::SendConfigUpdate(const ConfigObject::Ptr& object, bool runtimeUpd
 void IcingaDB::AddObjectDataToRuntimeUpdates(std::vector<Dictionary::Ptr>& runtimeUpdates, const String& objectKey,
 		const String& redisKey, const Dictionary::Ptr& data)
 {
-	data->Set("id", objectKey);
-	data->Set("redis_key", redisKey);
-	data->Set("runtime_type", "upsert");
-	runtimeUpdates.emplace_back(data);
+	Dictionary::Ptr dataClone = data->ShallowClone();
+	dataClone->Set("id", objectKey);
+	dataClone->Set("redis_key", redisKey);
+	dataClone->Set("runtime_type", "upsert");
+	runtimeUpdates.emplace_back(dataClone);
 }
 
 // Takes object and collects IcingaDB relevant attributes and computes checksums. Returns whether the object is relevant
@@ -1456,7 +1496,8 @@ IcingaDB::CreateConfigUpdate(const ConfigObject::Ptr& object, const String typeN
 
 void IcingaDB::SendConfigDelete(const ConfigObject::Ptr& object)
 {
-	String typeName = object->GetReflectionType()->GetName().ToLower();
+	Type::Ptr type = object->GetReflectionType();
+	String typeName = type->GetName().ToLower();
 	String objectKey = GetObjectIdentifier(object);
 
 	m_Rcon->FireAndForgetQueries({
@@ -1468,12 +1509,23 @@ void IcingaDB::SendConfigDelete(const ConfigObject::Ptr& object)
 		}
    	}, Prio::Config);
 
-	auto checkable (dynamic_pointer_cast<Checkable>(object));
+	CustomVarObject::Ptr customVarObject = dynamic_pointer_cast<CustomVarObject>(object);
+
+	if (customVarObject) {
+		Dictionary::Ptr vars = customVarObject->GetVars();
+		SendCustomVarsChanged(object, vars, nullptr);
+	}
+
+	if (type == Host::TypeInstance || type == Service::TypeInstance) {
+		Checkable::Ptr checkable = static_pointer_cast<Checkable>(object);
+
+		Host::Ptr host;
+		Service::Ptr service;
+		tie(host, service) = GetHostService(checkable);
 
-	if (checkable) {
 		m_Rcon->FireAndForgetQuery({
 			"ZREM",
-			dynamic_pointer_cast<Service>(checkable) ? "icinga:nextupdate:service" : "icinga:nextupdate:host",
+			service ? "icinga:nextupdate:service" : "icinga:nextupdate:host",
 			GetObjectIdentifier(checkable)
 		}, Prio::CheckResult);
 
@@ -1481,6 +1533,42 @@ void IcingaDB::SendConfigDelete(const ConfigObject::Ptr& object)
 			{"HDEL", m_PrefixConfigObject + typeName + ":state", objectKey},
 			{"HDEL", m_PrefixConfigCheckSum + typeName + ":state", objectKey}
 		}, Prio::RuntimeStateSync);
+
+		if (service) {
+			SendGroupsChanged<ServiceGroup>(checkable, service->GetGroups(), nullptr);
+		} else {
+			SendGroupsChanged<HostGroup>(checkable, host->GetGroups(), nullptr);
+		}
+
+		return;
+	}
+
+	if (type == TimePeriod::TypeInstance) {
+		TimePeriod::Ptr timeperiod = static_pointer_cast<TimePeriod>(object);
+		SendTimePeriodRangesChanged(timeperiod, timeperiod->GetRanges(), nullptr);
+		SendTimePeriodIncludesChanged(timeperiod, timeperiod->GetIncludes(), nullptr);
+		SendTimePeriodExcludesChanged(timeperiod, timeperiod->GetExcludes(), nullptr);
+		return;
+	}
+
+	if (type == User::TypeInstance) {
+		User::Ptr user = static_pointer_cast<User>(object);
+		SendGroupsChanged<UserGroup>(user, user->GetGroups(), nullptr);
+		return;
+	}
+
+	if (type == Notification::TypeInstance) {
+		Notification::Ptr notification = static_pointer_cast<Notification>(object);
+		SendNotificationUsersChanged(notification, notification->GetUsersRaw(), nullptr);
+		SendNotificationUserGroupsChanged(notification, notification->GetUserGroupsRaw(), nullptr);
+		return;
+	}
+
+	if (type == CheckCommand::TypeInstance || type == NotificationCommand::TypeInstance || type == EventCommand::TypeInstance) {
+		Command::Ptr command = static_pointer_cast<Command>(object);
+		SendCommandArgumentsChanged(command, command->GetArguments(), nullptr);
+		SendCommandEnvChanged(command, command->GetEnv(), nullptr);
+		return;
 	}
 }
 
@@ -2174,6 +2262,150 @@ void IcingaDB::SendAcknowledgementCleared(const Checkable::Ptr& checkable, const
 	m_Rcon->FireAndForgetQuery(std::move(xAdd), Prio::History);
 }
 
+void IcingaDB::SendNotificationUsersChanged(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<Value> deletedUsers = GetArrayDeletedValues(oldValues, newValues);
+
+	for (const auto& userName : deletedUsers) {
+		String id = HashValue(new Array({m_EnvironmentId, "user", userName, notification->GetName()}));
+		DeleteRelationship(id, "notification:user");
+		DeleteRelationship(id, "notification:recipient");
+	}
+}
+
+void IcingaDB::SendNotificationUserGroupsChanged(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<Value> deletedUserGroups = GetArrayDeletedValues(oldValues, newValues);
+
+	for (const auto& userGroupName : deletedUserGroups) {
+		UserGroup::Ptr userGroup = UserGroup::GetByName(userGroupName);
+		String id = HashValue(new Array({m_EnvironmentId, "usergroup", userGroupName, notification->GetName()}));
+		DeleteRelationship(id, "notification:usergroup");
+		DeleteRelationship(id, "notification:recipient");
+
+		for (const User::Ptr& user : userGroup->GetMembers()) {
+			String userId = HashValue(new Array({m_EnvironmentId, "usergroupuser", user->GetName(), userGroupName, notification->GetName()}));
+			DeleteRelationship(userId, "notification:recipient");
+		}
+	}
+}
+
+void IcingaDB::SendTimePeriodRangesChanged(const TimePeriod::Ptr& timeperiod, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<String> deletedKeys = GetDictionaryDeletedKeys(oldValues, newValues);
+	String typeName = GetLowerCaseTypeNameDB(timeperiod);
+
+	for (const auto& rangeKey : deletedKeys) {
+		String id = HashValue(new Array({m_EnvironmentId, rangeKey, oldValues->Get(rangeKey), timeperiod->GetName()}));
+		DeleteRelationship(id, "timeperiod:range");
+	}
+}
+
+void IcingaDB::SendTimePeriodIncludesChanged(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<Value> deletedIncludes = GetArrayDeletedValues(oldValues, newValues);
+
+	for (const auto& includeName : deletedIncludes) {
+		String id = HashValue(new Array({m_EnvironmentId, includeName, timeperiod->GetName()}));
+		DeleteRelationship(id, "timeperiod:override:include");
+	}
+}
+
+void IcingaDB::SendTimePeriodExcludesChanged(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<Value> deletedExcludes = GetArrayDeletedValues(oldValues, newValues);
+
+	for (const auto& excludeName : deletedExcludes) {
+		String id = HashValue(new Array({m_EnvironmentId, excludeName, timeperiod->GetName()}));
+		DeleteRelationship(id, "timeperiod:override:exclude");
+	}
+}
+
+template<typename T>
+void IcingaDB::SendGroupsChanged(const ConfigObject::Ptr& object, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<Value> deletedGroups = GetArrayDeletedValues(oldValues, newValues);
+	String typeName = GetLowerCaseTypeNameDB(object);
+
+	for (const auto& groupName : deletedGroups) {
+		typename T::Ptr group = ConfigObject::GetObject<T>(groupName);
+		String id = HashValue(new Array({m_EnvironmentId, group->GetName(), object->GetName()}));
+		DeleteRelationship(id, typeName + "group:member");
+
+		if (std::is_same<T, UserGroup>::value) {
+			UserGroup::Ptr userGroup = dynamic_pointer_cast<UserGroup>(group);
+
+			for (const auto& notification : userGroup->GetNotifications()) {
+				String userId = HashValue(new Array({m_EnvironmentId, "usergroupuser", object->GetName(), groupName, notification->GetName()}));
+				DeleteRelationship(userId, "notification:recipient");
+			}
+		}
+	}
+}
+
+void IcingaDB::SendCommandEnvChanged(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<String> deletedKeys = GetDictionaryDeletedKeys(oldValues, newValues);
+	String typeName = GetLowerCaseTypeNameDB(command);
+
+	for (const auto& envvarKey : deletedKeys) {
+		String id = HashValue(new Array({m_EnvironmentId, envvarKey, command->GetName()}));
+		DeleteRelationship(id, typeName + ":envvar", true);
+	}
+}
+
+void IcingaDB::SendCommandArgumentsChanged(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	std::vector<String> deletedKeys = GetDictionaryDeletedKeys(oldValues, newValues);
+	String typeName = GetLowerCaseTypeNameDB(command);
+
+	for (const auto& argumentKey : deletedKeys) {
+		String id = HashValue(new Array({m_EnvironmentId, argumentKey, command->GetName()}));
+		DeleteRelationship(id, typeName + ":argument", true);
+	}
+}
+
+void IcingaDB::SendCustomVarsChanged(const ConfigObject::Ptr& object, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	if (!m_Rcon || !m_Rcon->IsConnected() || oldValues == newValues) {
+		return;
+	}
+
+	Dictionary::Ptr oldVars = SerializeVars(oldValues);
+	Dictionary::Ptr newVars = SerializeVars(newValues);
+
+	std::vector<String> deletedVars = GetDictionaryDeletedKeys(oldVars, newVars);
+	String typeName = GetLowerCaseTypeNameDB(object);
+
+	for (const auto& varId : deletedVars) {
+		String id = HashValue(new Array({m_EnvironmentId, varId, object->GetName()}));
+		DeleteRelationship(id, typeName + ":customvar");
+	}
+}
+
 Dictionary::Ptr IcingaDB::SerializeState(const Checkable::Ptr& checkable)
 {
 	Dictionary::Ptr attrs = new Dictionary();
@@ -2473,3 +2705,89 @@ void IcingaDB::AcknowledgementClearedHandler(const Checkable::Ptr& checkable, co
 		}
 	}
 }
+
+void IcingaDB::NotificationUsersChangedHandler(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendNotificationUsersChanged(notification, oldValues, newValues);
+	}
+}
+
+void IcingaDB::NotificationUserGroupsChangedHandler(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendNotificationUserGroupsChanged(notification, oldValues, newValues);
+	}
+}
+
+void IcingaDB::TimePeriodRangesChangedHandler(const TimePeriod::Ptr& timeperiod, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendTimePeriodRangesChanged(timeperiod, oldValues, newValues);
+	}
+}
+
+void IcingaDB::TimePeriodIncludesChangedHandler(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendTimePeriodIncludesChanged(timeperiod, oldValues, newValues);
+	}
+}
+
+void IcingaDB::TimePeriodExcludesChangedHandler(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendTimePeriodExcludesChanged(timeperiod, oldValues, newValues);
+	}
+}
+
+void IcingaDB::UserGroupsChangedHandler(const User::Ptr& user, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendGroupsChanged<UserGroup>(user, oldValues, newValues);
+	}
+}
+
+void IcingaDB::HostGroupsChangedHandler(const Host::Ptr& host, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendGroupsChanged<HostGroup>(host, oldValues, newValues);
+	}
+}
+
+void IcingaDB::ServiceGroupsChangedHandler(const Service::Ptr& service, const Array::Ptr& oldValues, const Array::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendGroupsChanged<ServiceGroup>(service, oldValues, newValues);
+	}
+}
+
+void IcingaDB::CommandEnvChangedHandler(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendCommandEnvChanged(command, oldValues, newValues);
+	}
+}
+
+void IcingaDB::CommandArgumentsChangedHandler(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendCommandArgumentsChanged(command, oldValues, newValues);
+	}
+}
+
+void IcingaDB::CustomVarsChangedHandler(const ConfigObject::Ptr& object, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues) {
+	for (const IcingaDB::Ptr& rw : ConfigType::GetObjectsByType<IcingaDB>()) {
+		rw->SendCustomVarsChanged(object, oldValues, newValues);
+	}
+}
+
+void IcingaDB::DeleteRelationship(const String& id, const String& redisKeyWithoutPrefix, bool hasChecksum) {
+	Log(LogNotice, "IcingaDB") << "Deleting relationship '" << redisKeyWithoutPrefix << " -> '" << id << "'";
+
+	String redisKey = m_PrefixConfigObject + redisKeyWithoutPrefix;
+
+	std::vector<std::vector<String>> queries;
+
+	if (hasChecksum) {
+		queries.push_back({"HDEL", m_PrefixConfigCheckSum + redisKeyWithoutPrefix, id});
+	}
+
+	queries.push_back({"HDEL", redisKey, id});
+	queries.push_back({
+		"XADD", "icinga:runtime", "MAXLEN", "~", "1000000", "*",
+		"redis_key", redisKey, "id", id, "runtime_type", "delete"
+	});
+
+	m_Rcon->FireAndForgetQueries(queries, Prio::Config);
+}
diff --git a/lib/icingadb/icingadb-utility.cpp b/lib/icingadb/icingadb-utility.cpp
index dbb7fa818..f82625019 100644
--- a/lib/icingadb/icingadb-utility.cpp
+++ b/lib/icingadb/icingadb-utility.cpp
@@ -90,7 +90,7 @@ String IcingaDB::CalcEventID(const char* eventType, const ConfigObject::Ptr& obj
 static const std::set<String> metadataWhitelist ({"package", "source_location", "templates"});
 
 /**
- * Prepare object's custom vars for being written to Redis
+ * Prepare custom vars for being written to Redis
  *
  * object.vars = {
  *   "disks": {
@@ -124,14 +124,12 @@ static const std::set<String> metadataWhitelist ({"package", "source_location",
  *   }
  * }
  *
- * @param	object	Config object with custom vars
+ * @param	Dictionary	Config object with custom vars
  *
- * @return 			JSON-like data structure for Redis
+ * @return 				JSON-like data structure for Redis
  */
-Dictionary::Ptr IcingaDB::SerializeVars(const CustomVarObject::Ptr& object)
+Dictionary::Ptr IcingaDB::SerializeVars(const Dictionary::Ptr& vars)
 {
-	Dictionary::Ptr vars = object->GetVars();
-
 	if (!vars)
 		return nullptr;
 
@@ -258,3 +256,49 @@ String IcingaDB::IcingaToStreamValue(const Value& value)
 			return JsonEncode(value);
 	}
 }
+
+// Returns the items that exist in "arrayOld" but not in "arrayNew"
+std::vector<Value> IcingaDB::GetArrayDeletedValues(const Array::Ptr& arrayOld, const Array::Ptr& arrayNew) {
+	std::vector<Value> deletedValues;
+
+	if (!arrayOld) {
+		return deletedValues;
+	}
+
+	if (!arrayNew) {
+		return std::vector<Value>(arrayOld->Begin(), arrayOld->End());
+	}
+
+	std::vector<Value> vectorOld(arrayOld->Begin(), arrayOld->End());
+	std::sort(vectorOld.begin(), vectorOld.end());
+	vectorOld.erase(std::unique(vectorOld.begin(), vectorOld.end()), vectorOld.end());
+
+	std::vector<Value> vectorNew(arrayNew->Begin(), arrayNew->End());
+	std::sort(vectorNew.begin(), vectorNew.end());
+	vectorNew.erase(std::unique(vectorNew.begin(), vectorNew.end()), vectorNew.end());
+
+	std::set_difference(vectorOld.begin(), vectorOld.end(), vectorNew.begin(), vectorNew.end(), std::back_inserter(deletedValues));
+
+	return deletedValues;
+}
+
+// Returns the keys that exist in "dictOld" but not in "dictNew"
+std::vector<String> IcingaDB::GetDictionaryDeletedKeys(const Dictionary::Ptr& dictOld, const Dictionary::Ptr& dictNew) {
+	std::vector<String> deletedKeys;
+
+	if (!dictOld) {
+		return deletedKeys;
+	}
+
+	std::vector<String> oldKeys = dictOld->GetKeys();
+
+	if (!dictNew) {
+		return oldKeys;
+	}
+
+	std::vector<String> newKeys = dictNew->GetKeys();
+
+	std::set_difference(oldKeys.begin(), oldKeys.end(), newKeys.begin(), newKeys.end(), std::back_inserter(deletedKeys));
+
+	return deletedKeys;
+}
diff --git a/lib/icingadb/icingadb.hpp b/lib/icingadb/icingadb.hpp
index 168bd2f00..7a392a2ad 100644
--- a/lib/icingadb/icingadb.hpp
+++ b/lib/icingadb/icingadb.hpp
@@ -79,6 +79,7 @@ private:
 	void SendStateChange(const ConfigObject::Ptr& object, const CheckResult::Ptr& cr, StateType type);
 	void AddObjectDataToRuntimeUpdates(std::vector<Dictionary::Ptr>& runtimeUpdates, const String& objectKey,
 			const String& redisKey, const Dictionary::Ptr& data);
+	void DeleteRelationship(const String& id, const String& redisKeyWithoutPrefix, bool hasChecksum = false);
 
 	void SendSentNotification(
 		const Notification::Ptr& notification, const Checkable::Ptr& checkable, const std::set<User::Ptr>& users,
@@ -93,6 +94,16 @@ private:
 	void SendNextUpdate(const Checkable::Ptr& checkable);
 	void SendAcknowledgementSet(const Checkable::Ptr& checkable, const String& author, const String& comment, AcknowledgementType type, bool persistent, double changeTime, double expiry);
 	void SendAcknowledgementCleared(const Checkable::Ptr& checkable, const String& removedBy, double changeTime, double ackLastChange);
+	void SendNotificationUsersChanged(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	void SendNotificationUserGroupsChanged(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	void SendTimePeriodRangesChanged(const TimePeriod::Ptr& timeperiod, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	void SendTimePeriodIncludesChanged(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	void SendTimePeriodExcludesChanged(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	template<class T>
+	void SendGroupsChanged(const ConfigObject::Ptr& command, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	void SendCommandEnvChanged(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	void SendCommandArgumentsChanged(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	void SendCustomVarsChanged(const ConfigObject::Ptr& object, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
 
 	std::vector<String> UpdateObjectAttrs(const ConfigObject::Ptr& object, int fieldType, const String& typeNameOverride);
 	Dictionary::Ptr SerializeState(const Checkable::Ptr& checkable);
@@ -105,11 +116,13 @@ private:
 	static String FormatCommandLine(const Value& commandLine);
 	static long long TimestampToMilliseconds(double timestamp);
 	static String IcingaToStreamValue(const Value& value);
+	static std::vector<Value> GetArrayDeletedValues(const Array::Ptr& arrayOld, const Array::Ptr& arrayNew);
+	static std::vector<String> GetDictionaryDeletedKeys(const Dictionary::Ptr& dictOld, const Dictionary::Ptr& dictNew);
 
 	static String GetObjectIdentifier(const ConfigObject::Ptr& object);
 	static String CalcEventID(const char* eventType, const ConfigObject::Ptr& object, double eventTime = 0, NotificationType nt = NotificationType(0));
-	static Dictionary::Ptr SerializeVars(const CustomVarObject::Ptr& object);
 	static const char* GetNotificationTypeByEnum(NotificationType type);
+	static Dictionary::Ptr SerializeVars(const Dictionary::Ptr& vars);
 
 	static String HashValue(const Value& value);
 	static String HashValue(const Value& value, const std::set<String>& propertiesBlacklist, bool propertiesWhitelist = false);
@@ -135,6 +148,17 @@ private:
 	static void NextCheckChangedHandler(const Checkable::Ptr& checkable);
 	static void AcknowledgementSetHandler(const Checkable::Ptr& checkable, const String& author, const String& comment, AcknowledgementType type, bool persistent, double changeTime, double expiry);
 	static void AcknowledgementClearedHandler(const Checkable::Ptr& checkable, const String& removedBy, double changeTime);
+	static void NotificationUsersChangedHandler(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void NotificationUserGroupsChangedHandler(const Notification::Ptr& notification, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void TimePeriodRangesChangedHandler(const TimePeriod::Ptr& timeperiod, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	static void TimePeriodIncludesChangedHandler(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void TimePeriodExcludesChangedHandler(const TimePeriod::Ptr& timeperiod, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void UserGroupsChangedHandler(const User::Ptr& user, const Array::Ptr&, const Array::Ptr& newValues);
+	static void HostGroupsChangedHandler(const Host::Ptr& host, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void ServiceGroupsChangedHandler(const Service::Ptr& service, const Array::Ptr& oldValues, const Array::Ptr& newValues);
+	static void CommandEnvChangedHandler(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	static void CommandArgumentsChangedHandler(const ConfigObject::Ptr& command, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
+	static void CustomVarsChangedHandler(const ConfigObject::Ptr& object, const Dictionary::Ptr& oldValues, const Dictionary::Ptr& newValues);
 
 	void AssertOnWorkQueue();
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 25557944a..ba08fa431 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -70,6 +70,7 @@ add_boost_test(base
     base_dictionary/remove
     base_dictionary/clone
     base_dictionary/json
+    base_dictionary/keys_ordered
     base_fifo/construct
     base_fifo/io
     base_json/encode
diff --git a/test/base-dictionary.cpp b/test/base-dictionary.cpp
index cd074e1a9..3469be7cd 100644
--- a/test/base-dictionary.cpp
+++ b/test/base-dictionary.cpp
@@ -3,6 +3,8 @@
 #include "base/dictionary.hpp"
 #include "base/objectlock.hpp"
 #include "base/json.hpp"
+#include "base/string.hpp"
+#include "base/utility.hpp"
 #include <BoostTestTargetConfig.h>
 
 using namespace icinga;
@@ -183,4 +185,16 @@ BOOST_AUTO_TEST_CASE(json)
 	BOOST_CHECK(deserialized->Get("test2") == "hello world");
 }
 
+BOOST_AUTO_TEST_CASE(keys_ordered)
+{
+	Dictionary::Ptr dictionary = new Dictionary();
+
+	for (int i = 0; i < 100; i++) {
+		dictionary->Set(std::to_string(Utility::Random()), Utility::Random());
+	}
+
+	std::vector<String> keys = dictionary->GetKeys();
+	BOOST_CHECK(std::is_sorted(keys.begin(), keys.end()));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/tools/mkclass/class_lexer.ll b/tools/mkclass/class_lexer.ll
index 56f219a76..217ca492c 100644
--- a/tools/mkclass/class_lexer.ll
+++ b/tools/mkclass/class_lexer.ll
@@ -134,6 +134,7 @@ no_user_view			{ yylval->num = FANoUserView; return T_FIELD_ATTRIBUTE; }
 deprecated			{ yylval->num = FADeprecated; return T_FIELD_ATTRIBUTE; }
 get_virtual			{ yylval->num = FAGetVirtual; return T_FIELD_ATTRIBUTE; }
 set_virtual			{ yylval->num = FASetVirtual; return T_FIELD_ATTRIBUTE; }
+signal_with_old_value			{ yylval->num = FASignalWithOldValue; return T_FIELD_ATTRIBUTE; }
 virtual				{ yylval->num = FAGetVirtual | FASetVirtual; return T_FIELD_ATTRIBUTE; }
 navigation			{ return T_NAVIGATION; }
 validator			{ return T_VALIDATOR; }
diff --git a/tools/mkclass/classcompiler.cpp b/tools/mkclass/classcompiler.cpp
index f6793da50..09110bdee 100644
--- a/tools/mkclass/classcompiler.cpp
+++ b/tools/mkclass/classcompiler.cpp
@@ -830,10 +830,10 @@ void ClassCompiler::HandleClass(const Klass& klass, const ClassDebugInfo&)
 				m_Impl << "void ObjectImpl<" << klass.Name << ">::Set" << field.GetFriendlyName() << "(" << field.Type.GetArgumentType() << " value, bool suppress_events, const Value& cookie)" << std::endl
 					<< "{" << std::endl;
 
-				if (field.Type.IsName || !field.TrackAccessor.empty())
-					m_Impl << "\t" << "Value oldValue = Get" << field.GetFriendlyName() << "();" << std::endl;
+				if (field.Type.IsName || !field.TrackAccessor.empty() || field.Attributes & FASignalWithOldValue)
+					m_Impl << "\t" << "Value oldValue = Get" << field.GetFriendlyName() << "();" << std::endl
+						<< "\t" << "auto *dobj = dynamic_cast<ConfigObject *>(this);" << std::endl;
 
-					
 				if (field.SetAccessor.empty() && !(field.Attributes & FANoStorage))
 					m_Impl << "\t" << "m_" << field.GetFriendlyName() << ".store(value);" << std::endl;
 				else
@@ -841,16 +841,22 @@ void ClassCompiler::HandleClass(const Klass& klass, const ClassDebugInfo&)
 
 				if (field.Type.IsName || !field.TrackAccessor.empty()) {
 					if (field.Name != "active") {
-						m_Impl << "\t" << "auto *dobj = dynamic_cast<ConfigObject *>(this);" << std::endl
-							<< "\t" << "if (!dobj || dobj->IsActive())" << std::endl
+						m_Impl << "\t" << "if (!dobj || dobj->IsActive())" << std::endl
 							<< "\t";
 					}
 
 					m_Impl << "\t" << "Track" << field.GetFriendlyName() << "(oldValue, value);" << std::endl;
 				}
 
-				m_Impl << "\t" << "if (!suppress_events)" << std::endl
-					<< "\t\t" << "Notify" << field.GetFriendlyName() << "(cookie);" << std::endl
+				m_Impl << "\t" << "if (!suppress_events) {" << std::endl
+					<< "\t\t" << "Notify" << field.GetFriendlyName() << "(cookie);" << std::endl;
+
+				if (field.Attributes & FASignalWithOldValue) {
+					m_Impl << "\t\t" << "if (!dobj || dobj->IsActive())" << std::endl
+						   << "\t\t\t" << "On" << field.GetFriendlyName() << "ChangedWithOldValue(static_cast<" << klass.Name << " *>(this), oldValue, value);" << std::endl;
+				}
+
+				m_Impl << "\t" "}" << std::endl << std::endl
 					<< "}" << std::endl << std::endl;
 			}
 		}
@@ -1053,6 +1059,15 @@ void ClassCompiler::HandleClass(const Klass& klass, const ClassDebugInfo&)
 		for (const Field& field : klass.Fields) {
 			m_Header << "\t" << "static boost::signals2::signal<void (const intrusive_ptr<" << klass.Name << ">&, const Value&)> On" << field.GetFriendlyName() << "Changed;" << std::endl;
 			m_Impl << std::endl << "boost::signals2::signal<void (const intrusive_ptr<" << klass.Name << ">&, const Value&)> ObjectImpl<" << klass.Name << ">::On" << field.GetFriendlyName() << "Changed;" << std::endl << std::endl;
+
+			if (field.Attributes & FASignalWithOldValue) {
+				m_Header << "\t" << "static boost::signals2::signal<void (const intrusive_ptr<" << klass.Name
+					<< ">&, const Value&, const Value&)> On" << field.GetFriendlyName() << "ChangedWithOldValue;"
+					<< std::endl;
+				m_Impl << std::endl << "boost::signals2::signal<void (const intrusive_ptr<" << klass.Name
+					<< ">&, const Value&, const Value&)> ObjectImpl<" << klass.Name << ">::On"
+					<< field.GetFriendlyName() << "ChangedWithOldValue;" << std::endl << std::endl;
+			}
 		}
 	}
 
diff --git a/tools/mkclass/classcompiler.hpp b/tools/mkclass/classcompiler.hpp
index c05de11a7..0bd789dd3 100644
--- a/tools/mkclass/classcompiler.hpp
+++ b/tools/mkclass/classcompiler.hpp
@@ -60,7 +60,8 @@ enum FieldAttribute
 	FADeprecated = 4096,
 	FAGetVirtual = 8192,
 	FASetVirtual = 16384,
-	FAActivationPriority = 32768
+	FAActivationPriority = 32768,
+	FASignalWithOldValue = 65536,
 };
 
 struct FieldType