diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h
index f8ac13ebb74..0c25b6d8237 100644
--- a/src/widgets/kernel/qwidget_p.h
+++ b/src/widgets/kernel/qwidget_p.h
@@ -888,9 +888,15 @@ inline void QWidgetPrivate::setSharedPainter(QPainter *painter)
 inline bool QWidgetPrivate::pointInsideRectAndMask(const QPointF &p) const
 {
     Q_Q(const QWidget);
-    // Use QRectF::contains so that (0, -0.1) isn't in, with p.toPoint() it would be
-    // The adjusted matches QRect semantics: (160,160) isn't contained in QRect(0, 0, 160, 160)
-    return QRectF(q->rect().adjusted(0, 0, -1, -1)).contains(p)
+
+    // Use QRectF::contains so that (0, -0.1) isn't in, with p.toPoint() it would be in.
+    // The -1 on right and bottom matches QRect semantics:
+    // (160,160) isn't contained in QRect(0, 0, 160, 160)
+    QRect r = q->rect();
+    r.setRight(qMax(-1, r.right() - 1));
+    r.setBottom(qMax(-1, r.bottom() - 1));
+
+    return r.toRectF().contains(p)
             && (!extra || !extra->hasMask || q->testAttribute(Qt::WA_MouseNoMask)
                 || extra->mask.contains(p.toPoint() /* incorrect for the -0.1 case */));
 }
diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index c880146a971..7da9457d85d 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -11775,11 +11775,27 @@ void tst_QWidget::childAt()
     grandChild->setAutoFillBackground(true);
     grandChild->setGeometry(-20, -20, 220, 220);
 
+    QWidget *emptyChild = new QWidget(child);
+    emptyChild->setPalette(Qt::green);
+    emptyChild->setAutoFillBackground(true);
+    emptyChild->setGeometry(0, 159, 160, 0);
+
     QVERIFY(!parent.childAt(19, 19));
     QVERIFY(!parent.childAt(180, 180));
     QCOMPARE(parent.childAt(20, 20), grandChild);
     QCOMPARE(parent.childAt(179, 179), grandChild);
 
+    QCOMPARE(parent.childAt(120, 179), grandChild);
+    QCOMPARE(parent.childAt(QPointF(120.0, 178.9)), grandChild);
+    QVERIFY(!parent.childAt(120, 180));
+    QVERIFY(!parent.childAt(QPointF(120, 179.1)));
+
+    emptyChild->setGeometry(100, 0, 0, 160);
+
+    QCOMPARE(parent.childAt(120, 120), grandChild);
+    QCOMPARE(parent.childAt(QPointF(120.5, 120.0)), grandChild);
+    QCOMPARE(parent.childAt(QPointF(119.5, 120.0)), grandChild);
+
     grandChild->setAttribute(Qt::WA_TransparentForMouseEvents);
     QCOMPARE(parent.childAt(20, 20), child);
     QCOMPARE(parent.childAt(179, 179), child);