diff --git a/src/chartpresenter.cpp b/src/chartpresenter.cpp
index 564a0d0..b11cd39 100644
--- a/src/chartpresenter.cpp
+++ b/src/chartpresenter.cpp
@@ -62,6 +62,7 @@ void ChartPresenter::handleGeometryChanged()
 {
     m_rect = QRectF(QPoint(0,0),m_chart->size());
     m_rect.adjust(m_marginSize,m_marginSize, -m_marginSize, -m_marginSize);
+    Q_ASSERT(m_rect.isValid());
     emit geometryChanged(m_rect);
 }
 
diff --git a/test/chartwidgettest/main.cpp b/test/chartwidgettest/main.cpp
index cc1e7c1..7052796 100644
--- a/test/chartwidgettest/main.cpp
+++ b/test/chartwidgettest/main.cpp
@@ -11,6 +11,7 @@ int main(int argc, char *argv[])
     QApplication a(argc, argv);
 
     MainWidget w;
+    w.resize(1000,600);
     w.show();
 
     return a.exec();