diff --git a/sources/diagram.cpp b/sources/diagram.cpp
index 538cca151..94200bfe5 100644
--- a/sources/diagram.cpp
+++ b/sources/diagram.cpp
@@ -137,15 +137,20 @@ Diagram::~Diagram()
 	delete m_event_interface;
 
 	// list removable items
-	QList<QGraphicsItem *> deletable_items;
-	for(QGraphicsItem *qgi : items())
+	QVector<QGraphicsItem *> deletable_items;
+	for(const auto &qgi : items())
 	{
-		if (qgi -> parentItem()) continue;
-		if (qgraphicsitem_cast<Conductor *>(qgi)) continue;
-		deletable_items << qgi;
+		if (qgi->parentItem())
+			continue;
+		if (qgraphicsitem_cast<Conductor *>(qgi))
+			continue;
+		deletable_items.append(qgi);
+	}
+	for (const auto &item : qAsConst(deletable_items))
+	{
+		removeItem(item);
+		delete item;
 	}
-
-	qDeleteAll (deletable_items);
 }
 
 /**
diff --git a/sources/qetgraphicsitem/ViewItem/qetgraphicsheaderitem.h b/sources/qetgraphicsitem/ViewItem/qetgraphicsheaderitem.h
index 2bc627318..c840bb3d2 100644
--- a/sources/qetgraphicsitem/ViewItem/qetgraphicsheaderitem.h
+++ b/sources/qetgraphicsitem/ViewItem/qetgraphicsheaderitem.h
@@ -84,7 +84,7 @@ class QetGraphicsHeaderItem : public QGraphicsObject
 
 		QRect m_current_rect;
 		QRectF m_bounding_rect;
-		QAbstractItemModel *m_model = nullptr;
+		QPointer<QAbstractItemModel> m_model;
 
 		QVector<int>
 		m_sections_minimum_width,
diff --git a/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.cpp b/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.cpp
index 9c4de8b92..389058f11 100644
--- a/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.cpp
+++ b/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.cpp
@@ -185,7 +185,7 @@ void QetGraphicsTableItem::setModel(QAbstractItemModel *model)
 			   this, &QetGraphicsTableItem::modelReseted);
 	}
 	m_model = model;
-	m_header_item->setModel(model);
+	m_header_item->setModel(m_model);
 
 	setUpColumnAndRowMinimumSize();
 	adjustSize();
@@ -210,7 +210,7 @@ void QetGraphicsTableItem::setModel(QAbstractItemModel *model)
 */
 QAbstractItemModel *QetGraphicsTableItem::model() const
 {
-	return m_model;
+	return m_model.data();
 }
 
 /**
@@ -599,7 +599,7 @@ QDomElement QetGraphicsTableItem::toXml(QDomDocument &dom_document) const
 	{
 			//Add model
 		auto dom_model = dom_document.createElement("model");
-		auto project_db_model = static_cast<ProjectDBModel *>(m_model);
+		auto project_db_model = static_cast<ProjectDBModel *>(m_model.data());
 		dom_model.appendChild(project_db_model->toXml(dom_document));
 		dom_table.appendChild(dom_model);
 
diff --git a/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.h b/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.h
index c7cf58473..25ccf5d04 100644
--- a/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.h
+++ b/sources/qetgraphicsitem/ViewItem/qetgraphicstableitem.h
@@ -123,7 +123,7 @@ class QetGraphicsTableItem : public QetGraphicsItem
 		void previousTableDisplayRowChanged();
 		void removeUselessNextTable(bool recursive = true);
 
-		QAbstractItemModel *m_model= nullptr;
+		QPointer<QAbstractItemModel> m_model;
 
 		QVector<int> m_minimum_column_width;
 		int