diff --git a/src/libs/vtools/tools/vtooldetail.cpp b/src/libs/vtools/tools/vtooldetail.cpp
index 7694f92cf..495591597 100644
--- a/src/libs/vtools/tools/vtooldetail.cpp
+++ b/src/libs/vtools/tools/vtooldetail.cpp
@@ -420,9 +420,16 @@ void VToolDetail::paint(QPainter *painter, const QStyleOptionGraphicsItem *optio
 {
     if (scene()->views().count() > 0)
     {
-        QPoint pt0 = scene()->views().at(0)->mapFromScene(0, 0);
-        QPoint pt = scene()->views().at(0)->mapFromScene(0, 100);
-        qreal dScale = qSqrt(QPoint::dotProduct(pt - pt0, pt - pt0));
+        const QPoint pt0 = scene()->views().at(0)->mapFromScene(0, 0);
+        const QPoint pt = scene()->views().at(0)->mapFromScene(0, 100);
+
+        const QPoint p = pt - pt0;
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+        const qreal dScale = qSqrt(QPoint::dotProduct(p, p));
+#else
+        const qreal dScale = qSqrt(p.xp * p.xp + p.yp * p.yp);
+#endif //QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
         grainLine->SetScale(100/dScale);
         //qDebug() << "SCALE" << dScale << 10/dScale;
     }