diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
index 2f759158ee6..6c34af1f9f8 100644
--- a/src/gui/kernel/qhighdpiscaling.cpp
+++ b/src/gui/kernel/qhighdpiscaling.cpp
@@ -540,8 +540,10 @@ static const char scaleFactorProperty[] = "_q_scaleFactor";
 /*
     Sets a per-screen scale factor.
 */
-void QHighDpiScaling::setScreenFactor(QScreen *screen, qreal factor)
+void QHighDpiScaling::setScreenFactor(QScreen *screen, qreal rawFactor)
 {
+    qreal factor = roundScaleFactor(rawFactor);
+
     if (!qFuzzyCompare(factor, qreal(1))) {
         m_screenFactorSet = true;
         m_active = true;
diff --git a/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp b/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
index f221c9db909..62f61e43fa7 100644
--- a/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
+++ b/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
@@ -313,9 +313,10 @@ void tst_QHighDpi::environment_QT_SCREEN_SCALE_FACTORS()
     QFETCH(QByteArray, environment);
     QFETCH(QList<qreal>, expectedDprValues);
 
+    qputenv("QT_SCREEN_SCALE_FACTORS", environment);
+
     // Verify that setting QT_SCREEN_SCALE_FACTORS overrides the from-platform-screen-DPI DPR.
     {
-        qputenv("QT_SCREEN_SCALE_FACTORS", environment);
         std::unique_ptr<QGuiApplication> app(createStandardOffscreenApp(platformScreenDpi));
         int i = 0;
         for (QScreen *screen : app->screens()) {
@@ -327,6 +328,18 @@ void tst_QHighDpi::environment_QT_SCREEN_SCALE_FACTORS()
             QCOMPARE(window.devicePixelRatio(), expextedDpr);
         }
     }
+
+    // Verify that setHighDpiScaleFactorRoundingPolicy applies to QT_SCREEN_SCALE_FACTORS as well
+    QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::Round);
+    {
+        std::unique_ptr<QGuiApplication> app(createStandardOffscreenApp(platformScreenDpi));
+        int i = 0;
+        for (QScreen *screen : app->screens()) {
+            qreal expectedRounderDpr = qRound(expectedDprValues[i++]);
+            qreal windowDpr = QWindow(screen).devicePixelRatio();
+            QCOMPARE(windowDpr, expectedRounderDpr);
+        }
+    }
 }
 
 void tst_QHighDpi::environment_QT_USE_PHYSICAL_DPI()