2 files changed, 5 insertions, 3 deletions
diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index b5dd3026a9..3bce7827bc 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -986,7 +986,9 @@ QSize QQuickWidget::initialSize() const
 }
 
 /*!
-  Returns the view's root \l {QQuickItem} {item}.
+  Returns the view's root \l {QQuickItem} {item}. Can be null
+  when setContents/setSource has not been called, if they were called with
+  broken QtQuick code or while the QtQuick contents are being created.
  */
 QQuickItem *QQuickWidget::rootObject() const
 {
diff --git a/src/quickwidgets/qquickwidget.h b/src/quickwidgets/qquickwidget.h
index 688cafd475..0732c506bb 100644
--- a/src/quickwidgets/qquickwidget.h
+++ b/src/quickwidgets/qquickwidget.h
@@ -64,9 +64,9 @@ class Q_QUICKWIDGETS_EXPORT QQuickWidget : public QWidget
     Q_PROPERTY(QUrl source READ source WRITE setSource DESIGNABLE true)
 
 public:
-    explicit QQuickWidget(QWidget *parent = 0);
+    explicit QQuickWidget(QWidget *parent = Q_NULLPTR);
     QQuickWidget(QQmlEngine* engine, QWidget *parent);
-    QQuickWidget(const QUrl &source, QWidget *parent = 0);
+    explicit QQuickWidget(const QUrl &source, QWidget *parent = Q_NULLPTR);
     virtual ~QQuickWidget();
 
     QUrl source() const;