diff --git a/src/plugins/diagram_overlay/qgsdiagramdialog.h b/src/plugins/diagram_overlay/qgsdiagramdialog.h
diff --git a/src/plugins/diagram_overlay/qgsdiagramdialogbase.ui b/src/plugins/diagram_overlay/qgsdiagramdialogbase.ui
diff --git a/src/plugins/diagram_overlay/qgsdiagramfactorywidget.cpp b/src/plugins/diagram_overlay/qgsdiagramfactorywidget.cpp
diff --git a/src/plugins/diagram_overlay/qgsdiagramfactorywidget.h b/src/plugins/diagram_overlay/qgsdiagramfactorywidget.h
diff --git a/src/plugins/diagram_overlay/qgsdiagramoverlayplugin.cpp b/src/plugins/diagram_overlay/qgsdiagramoverlayplugin.cpp
@@ -18,26 +18,20 @@
 #include "qgsdiagramoverlayplugin.h"
 #include "qgisinterface.h"
 #include "qgslegendinterface.h"
-#include "qgsdiagramdialog.h"
 #include "qgsdiagramoverlay.h"
 #include "qgsmaplayerregistry.h"
 #include "qgsproject.h"
 #include "qgsvectorlayer.h"
 #include <QDomDocument>
 #include <QFile>
+#include <QWidget>
 
-#ifdef WIN32
-#define QGISEXTERN extern "C" __declspec( dllexport )
-#else
-#define QGISEXTERN extern "C"
-#endif
-
-static const QString pluginName = QObject::tr( "Diagram Overlay" );
+static const QString pluginName = QObject::tr( "Diagram Overlay (Legacy)" );
 static const QString pluginDescription = QObject::tr( "A plugin for placing diagrams on vector layers" );
 static const QString pluginCategory = QObject::tr( "Plugins" );
-static const QString pluginVersion = QObject::tr( "Version 0.0.1" );
+static const QString pluginVersion = QObject::tr( "Version 0.0.1 (Legacy)" );
 
-QgsDiagramOverlayPlugin::QgsDiagramOverlayPlugin( QgisInterface* iface ): QObject(), QgsVectorOverlayPlugin( pluginName, pluginDescription, pluginCategory, pluginVersion ), mInterface( iface )
+QgsDiagramOverlayPlugin::QgsDiagramOverlayPlugin( QgisInterface* iface ): QObject(), QgisPlugin( pluginName, pluginDescription, pluginCategory, pluginVersion, VECTOR_OVERLAY ), mInterface( iface )
 {
   if ( iface && iface->mainWindow() )
   {
@@ -122,11 +116,6 @@ void QgsDiagramOverlayPlugin::projectRead()
   }
 }
 
-QgsApplyDialog* QgsDiagramOverlayPlugin::dialog( QgsVectorLayer* vl ) const
-{
-  return new QgsDiagramDialog( vl );
-}
-
 QGISEXTERN QgisPlugin* classFactory( QgisInterface* iface )
 {
   return new QgsDiagramOverlayPlugin( iface );

diff --git a/src/plugins/diagram_overlay/qgsdiagramoverlayplugin.h b/src/plugins/diagram_overlay/qgsdiagramoverlayplugin.h
@@ -18,22 +18,21 @@
 #ifndef QGSDIAGRAMOVERLAYPLUGIN_H
 #define QGSDIAGRAMOVERLAYPLUGIN_H
 
-#include "qgsvectoroverlayplugin.h"
+#include "qgisplugin.h"
 #include <QObject>
 
 class QgisInterface;
 class QgsApplyDialog;
 
 /**A plugin for placing diagrams on vector layers. The plugin provides a widget that can be embedded into the
 vector layer properties dialog and is able to create and configure a diagram overlay layer*/
-class QgsDiagramOverlayPlugin: public QObject, public QgsVectorOverlayPlugin
+class QgsDiagramOverlayPlugin: public QObject, public QgisPlugin
 {
     Q_OBJECT
   public:
     QgsDiagramOverlayPlugin( QgisInterface* iface );
     ~QgsDiagramOverlayPlugin();
-    QgsApplyDialog* dialog( QgsVectorLayer* ) const;
-    void initGui() {}
+    void initGui() {};
     void unload() {}
 
   public slots:

diff --git a/src/plugins/diagram_overlay/qgsdiagramrendererwidget.cpp b/src/plugins/diagram_overlay/qgsdiagramrendererwidget.cpp
diff --git a/src/plugins/diagram_overlay/qgsdiagramrendererwidget.h b/src/plugins/diagram_overlay/qgsdiagramrendererwidget.h
diff --git a/src/plugins/diagram_overlay/qgslinearlyscalingdialog.cpp b/src/plugins/diagram_overlay/qgslinearlyscalingdialog.cpp
diff --git a/src/plugins/diagram_overlay/qgslinearlyscalingdialog.h b/src/plugins/diagram_overlay/qgslinearlyscalingdialog.h
diff --git a/src/plugins/diagram_overlay/qgslinearlyscalingdialogbase.ui b/src/plugins/diagram_overlay/qgslinearlyscalingdialogbase.ui
diff --git a/src/plugins/diagram_overlay/qgssvgdiagramfactorywidget.cpp b/src/plugins/diagram_overlay/qgssvgdiagramfactorywidget.cpp
diff --git a/src/plugins/diagram_overlay/qgssvgdiagramfactorywidget.h b/src/plugins/diagram_overlay/qgssvgdiagramfactorywidget.h
diff --git a/src/plugins/diagram_overlay/qgssvgdiagramfactorywidgetbase.ui b/src/plugins/diagram_overlay/qgssvgdiagramfactorywidgetbase.ui
diff --git a/src/plugins/diagram_overlay/qgswkndiagramfactorywidget.cpp b/src/plugins/diagram_overlay/qgswkndiagramfactorywidget.cpp
diff --git a/src/plugins/diagram_overlay/qgswkndiagramfactorywidget.h b/src/plugins/diagram_overlay/qgswkndiagramfactorywidget.h
diff --git a/src/plugins/diagram_overlay/qgswkndiagramfactorywidgetbase.ui b/src/plugins/diagram_overlay/qgswkndiagramfactorywidgetbase.ui