diff --git a/src/gui/opengl/qopenglpaintdevice.cpp b/src/gui/opengl/qopenglpaintdevice.cpp
index 32da27a078..ff4b76db01 100644
--- a/src/gui/opengl/qopenglpaintdevice.cpp
+++ b/src/gui/opengl/qopenglpaintdevice.cpp
@@ -83,10 +83,20 @@ public:
     bool flipped;
 
     QPaintEngine *engine;
-
-    void init(const QSize &size, QOpenGLContext *ctx);
 };
 
+/*!
+    Constructs a QOpenGLPaintDevice.
+
+    The QOpenGLPaintDevice is only valid for the current context.
+
+    \sa QOpenGLContext::currentContext()
+*/
+QOpenGLPaintDevice::QOpenGLPaintDevice()
+    : d_ptr(new QOpenGLPaintDevicePrivate(QSize()))
+{
+}
+
 /*!
     Constructs a QOpenGLPaintDevice with the given \a size.
 
@@ -166,6 +176,11 @@ QSize QOpenGLPaintDevice::size() const
     return d_ptr->size;
 }
 
+void QOpenGLPaintDevice::setSize(const QSize &size)
+{
+    d_ptr->size = size;
+}
+
 int QOpenGLPaintDevice::metric(QPaintDevice::PaintDeviceMetric metric) const
 {
     switch (metric) {
diff --git a/src/gui/opengl/qopenglpaintdevice.h b/src/gui/opengl/qopenglpaintdevice.h
index 7d4b901fe7..c1c3dfe9f8 100644
--- a/src/gui/opengl/qopenglpaintdevice.h
+++ b/src/gui/opengl/qopenglpaintdevice.h
@@ -71,6 +71,7 @@ class Q_GUI_EXPORT QOpenGLPaintDevice : public QPaintDevice
 {
     Q_DECLARE_PRIVATE(QOpenGLPaintDevice)
 public:
+    QOpenGLPaintDevice();
     explicit QOpenGLPaintDevice(const QSize &size);
     QOpenGLPaintDevice(int width, int height);
     virtual ~QOpenGLPaintDevice();
@@ -80,6 +81,7 @@ public:
 
     QOpenGLContext *context() const;
     QSize size() const;
+    void setSize(const QSize &size);
 
     qreal dotsPerMeterX() const;
     qreal dotsPerMeterY() const;