diff --git a/sources/factory/elementpicturefactory.cpp b/sources/factory/elementpicturefactory.cpp
index a00f011f9..4754d92d3 100644
--- a/sources/factory/elementpicturefactory.cpp
+++ b/sources/factory/elementpicturefactory.cpp
@@ -156,9 +156,9 @@ bool ElementPictureFactory::build(const ElementsLocation &location,
 		//Check if the current version can read the xml description
 	if (dom.hasAttribute("version"))
 	{
-		bool conv_ok;
-		qreal element_version = dom.attribute("version").toDouble(&conv_ok);
-		if (conv_ok && QET::version.toDouble() < element_version)
+		QVersionNumber qet_version = QVersionNumber::fromString(QET::version);
+		QVersionNumber element_version = QVersionNumber::fromString(dom.attribute("version"));
+		if (qet_version < element_version)
 		{
 			std::cerr << qPrintable(
 			QObject::tr("Avertissement : l'élément "
diff --git a/sources/qetgraphicsitem/element.cpp b/sources/qetgraphicsitem/element.cpp
index 5f5315444..5800a3072 100644
--- a/sources/qetgraphicsitem/element.cpp
+++ b/sources/qetgraphicsitem/element.cpp
@@ -429,10 +429,9 @@ bool Element::buildFromXml(const QDomElement &xml_def_elmt, int *state)
 		//Check if the current version can read the xml description
 	if (xml_def_elmt.hasAttribute(QStringLiteral("version")))
 	{
-		bool conv_ok;
-		qreal element_version = xml_def_elmt.attribute(
-					QStringLiteral("version")).toDouble(&conv_ok);
-		if (conv_ok && QET::version.toDouble() < element_version)
+		QVersionNumber qet_version = QVersionNumber::fromString(QET::version);
+		QVersionNumber element_version = QVersionNumber::fromString(xml_def_elmt.attribute(QStringLiteral("version")));
+		if (qet_version < element_version)
 		{
 			std::cerr << qPrintable(
 				QObject::tr("Avertissement : l'élément "
diff --git a/sources/qetproject.cpp b/sources/qetproject.cpp
index d7ded3bad..31914841a 100644
--- a/sources/qetproject.cpp
+++ b/sources/qetproject.cpp
@@ -436,7 +436,7 @@ QString QETProject::title() const
 	celui-ci a ete ouvert ; si ce projet n'a jamais ete enregistre / ouvert
 	depuis un fichier, cette methode retourne -1.
 */
-qreal QETProject::declaredQElectroTechVersion()
+QVersionNumber QETProject::declaredQElectroTechVersion()
 {
 	return(m_project_qet_version);
 }
@@ -1340,11 +1340,14 @@ void QETProject::readProjectXml(QDomDocument &xml_project)
 		if (root_elmt.hasAttribute(QStringLiteral("version")))
 		{
 			bool conv_ok;
-			m_project_qet_version = root_elmt.attribute(QStringLiteral("version")).toDouble(&conv_ok);
+			qreal r_project_qet_version = root_elmt.attribute(QStringLiteral("version")).toDouble(&conv_ok);
+			QVersionNumber qet_version = QVersionNumber::fromString(QET::version);
+			m_project_qet_version = QVersionNumber::fromString(root_elmt.attribute(QStringLiteral("version")));
+
 #if TODO_LIST
 #pragma message("@TODO use of version convert")
 #endif
-			if (conv_ok && QET::version.toDouble() < m_project_qet_version)
+			if (qet_version < m_project_qet_version)
 			{
 				int ret = QET::QetMessageBox::warning(
 							nullptr,
@@ -1365,9 +1368,11 @@ void QETProject::readProjectXml(QDomDocument &xml_project)
 					return;
 				}
 			}
+
 				//Since QElectrotech 0.9 the compatibility with project made with
 				//Qet 0.6 or lower is break;
-			if (conv_ok && m_project_qet_version <= 0.6 )
+				//keep float here for very old version
+			if (conv_ok && r_project_qet_version <= 0.6)
 			{
 				auto ret = QET::QetMessageBox::warning(
 							   nullptr,
diff --git a/sources/qetproject.h b/sources/qetproject.h
index ca160837a..687bdf6af 100644
--- a/sources/qetproject.h
+++ b/sources/qetproject.h
@@ -98,7 +98,7 @@ class QETProject : public QObject
 		QString currentDir() const;
 		QString pathNameTitle() const;
 		QString title() const;
-		qreal declaredQElectroTechVersion();
+		QVersionNumber declaredQElectroTechVersion();
 		void setTitle(const QString &);
 
 			///DEFAULT PROPERTIES
@@ -247,7 +247,7 @@ class QETProject : public QObject
 			/// Project title
 		QString project_title_;
 			/// QElectroTech version declared in the XML document at opening time
-		qreal m_project_qet_version = -1;
+		QVersionNumber m_project_qet_version;
 			/// Whether options were modified
 		bool m_modified = false;
 			/// Whether the project is read only