diff --git a/linphone-desktop/src/app/App.cpp b/linphone-desktop/src/app/App.cpp
index 125bd0b75..c930ce4d8 100644
--- a/linphone-desktop/src/app/App.cpp
+++ b/linphone-desktop/src/app/App.cpp
@@ -359,7 +359,7 @@ void App::registerTypes () {
   registerMetaType<ChatModel::EntryType>("ChatModel::EntryType");
 
   registerUncreatableType(CallModel, "CallModel");
-  registerUncreatableType(ConferenceAddModel, "ConferenceAddModel");
+  registerUncreatableType(ConferenceHelperModel::ConferenceAddModel, "ConferenceAddModel");
   registerUncreatableType(ContactModel, "ContactModel");
   registerUncreatableType(SipAddressObserver, "SipAddressObserver");
   registerUncreatableType(VcardModel, "VcardModel");
diff --git a/linphone-desktop/src/components/Components.hpp b/linphone-desktop/src/components/Components.hpp
index 1f7189641..fb798cf88 100644
--- a/linphone-desktop/src/components/Components.hpp
+++ b/linphone-desktop/src/components/Components.hpp
@@ -32,7 +32,6 @@
 #include "codecs/AudioCodecsModel.hpp"
 #include "codecs/VideoCodecsModel.hpp"
 #include "conference/ConferenceAddModel.hpp"
-#include "conference/ConferenceHelperModel.hpp"
 #include "contacts/ContactsListProxyModel.hpp"
 #include "core/CoreManager.hpp"
 #include "presence/OwnPresenceModel.hpp"
diff --git a/linphone-desktop/src/components/conference/ConferenceAddModel.cpp b/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
index 5f43f442c..85cdfba8d 100644
--- a/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
+++ b/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
@@ -22,7 +22,6 @@
 
 #include "../../Utils.hpp"
 #include "../core/CoreManager.hpp"
-#include "ConferenceHelperModel.hpp"
 
 #include "ConferenceAddModel.hpp"
 
@@ -30,7 +29,7 @@ using namespace std;
 
 // =============================================================================
 
-ConferenceAddModel::ConferenceAddModel (QObject *parent) : QAbstractListModel(parent) {
+ConferenceHelperModel::ConferenceAddModel::ConferenceAddModel (QObject *parent) : QAbstractListModel(parent) {
   mConferenceHelperModel = qobject_cast<ConferenceHelperModel *>(parent);
   Q_ASSERT(mConferenceHelperModel != nullptr);
 
@@ -38,17 +37,17 @@ ConferenceAddModel::ConferenceAddModel (QObject *parent) : QAbstractListModel(pa
     addToConference(participant);
 }
 
-int ConferenceAddModel::rowCount (const QModelIndex &) const {
+int ConferenceHelperModel::ConferenceAddModel::rowCount (const QModelIndex &) const {
   return mRefs.count();
 }
 
-QHash<int, QByteArray> ConferenceAddModel::roleNames () const {
+QHash<int, QByteArray> ConferenceHelperModel::ConferenceAddModel::roleNames () const {
   QHash<int, QByteArray> roles;
   roles[Qt::DisplayRole] = "$sipAddress";
   return roles;
 }
 
-QVariant ConferenceAddModel::data (const QModelIndex &index, int role) const {
+QVariant ConferenceHelperModel::ConferenceAddModel::data (const QModelIndex &index, int role) const {
   int row = index.row();
 
   if (!index.isValid() || row < 0 || row >= mRefs.count())
@@ -62,7 +61,7 @@ QVariant ConferenceAddModel::data (const QModelIndex &index, int role) const {
 
 // -----------------------------------------------------------------------------
 
-bool ConferenceAddModel::addToConference (const QString &sipAddress) {
+bool ConferenceHelperModel::ConferenceAddModel::addToConference (const QString &sipAddress) {
   if (mSipAddresses.contains(sipAddress))
     return false;
 
@@ -83,7 +82,7 @@ bool ConferenceAddModel::addToConference (const QString &sipAddress) {
   return true;
 }
 
-bool ConferenceAddModel::removeFromConference (const QString &sipAddress) {
+bool ConferenceHelperModel::ConferenceAddModel::removeFromConference (const QString &sipAddress) {
   auto it = mSipAddresses.find(sipAddress);
   if (it == mSipAddresses.end())
     return false;
@@ -106,7 +105,7 @@ bool ConferenceAddModel::removeFromConference (const QString &sipAddress) {
 
 // -----------------------------------------------------------------------------
 
-void ConferenceAddModel::update () {
+void ConferenceHelperModel::ConferenceAddModel::update () {
   list<shared_ptr<linphone::Address> > linphoneAddresses;
   for (const auto &map : mRefs)
     linphoneAddresses.push_back(map->value("__linphoneAddress").value<shared_ptr<linphone::Address> > ());
@@ -119,7 +118,7 @@ void ConferenceAddModel::update () {
 
 // -----------------------------------------------------------------------------
 
-void ConferenceAddModel::addToConference (const std::shared_ptr<linphone::Address> &linphoneAddress) {
+void ConferenceHelperModel::ConferenceAddModel::addToConference (const std::shared_ptr<linphone::Address> &linphoneAddress) {
   QString sipAddress = ::Utils::linphoneStringToQString(linphoneAddress->asStringUriOnly());
   QVariantMap map;
 
diff --git a/linphone-desktop/src/components/conference/ConferenceAddModel.hpp b/linphone-desktop/src/components/conference/ConferenceAddModel.hpp
index 8cc4c9e49..854d62ff6 100644
--- a/linphone-desktop/src/components/conference/ConferenceAddModel.hpp
+++ b/linphone-desktop/src/components/conference/ConferenceAddModel.hpp
@@ -25,17 +25,15 @@
 
 #include <memory>
 
-#include <QAbstractListModel>
+#include "ConferenceHelperModel.hpp"
 
 // =============================================================================
 
-class ConferenceHelperModel;
-
 namespace linphone {
   class Address;
 }
 
-class ConferenceAddModel : public QAbstractListModel {
+class ConferenceHelperModel::ConferenceAddModel : public QAbstractListModel {
   Q_OBJECT;
 
 public:
diff --git a/linphone-desktop/src/components/conference/ConferenceHelperModel.hpp b/linphone-desktop/src/components/conference/ConferenceHelperModel.hpp
index 00e5c73e2..2eca70ae0 100644
--- a/linphone-desktop/src/components/conference/ConferenceHelperModel.hpp
+++ b/linphone-desktop/src/components/conference/ConferenceHelperModel.hpp
@@ -37,13 +37,13 @@ namespace linphone {
 }
 
 class ConferenceHelperModel : public QSortFilterProxyModel {
-  friend class ConferenceAddModel;
-
   Q_OBJECT;
 
   Q_PROPERTY(ConferenceAddModel * toAdd READ getConferenceAddModel CONSTANT);
 
 public:
+  class ConferenceAddModel;
+
   ConferenceHelperModel (QObject *parent = Q_NULLPTR);
   ~ConferenceHelperModel () = default;