--- qtbase-opensource-src-5.7.1/src/plugins/platforms/xcb/qxcbscreen.cpp~
+++ qtbase-opensource-src-5.7.1/src/plugins/platforms/xcb/qxcbscreen.cpp
@@ -750,7 +750,7 @@ void QXcbScreen::updateGeometry(const QR
         m_sizeMillimeters = sizeInMillimeters(geometry.size(), virtualDpi());
 
     qreal dpi = geometry.width() / physicalSize().width() * qreal(25.4);
-    m_pixelDensity = qMax(1, qRound(dpi/96));
+    m_pixelDensity = qMax(1, (int)(dpi/96)); // instead of rounding at 1.5, round at 2.0 (same as GNOME)
     m_geometry = geometry;
     m_availableGeometry = geometry & m_virtualDesktop->workArea();
     QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), m_geometry, m_availableGeometry);