diff --git a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
index 3aff4af27b4577ae9f87e91119fa799ec20e3f2e..d31af2506753bef1d4999ce7be902be1a3aaa6a6 100644
--- a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
+++ b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
@@ -46,6 +46,7 @@
 #include <QSGAbstractRenderer>
 #include <QSGEngine>
 #include <QSGNode>
+#include <QWindow>
 
 static const int MaxTooltipLength = 1024;
 
diff --git a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.h b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.h
index 161b0bae6a193e996fbb504ed5087e4077a55b07..0b553d8eb0555e916a5e0132a52402977f8bcc6a 100644
--- a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.h
+++ b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.h
@@ -40,19 +40,16 @@
 #include "render_widget_host_view_qt_delegate.h"
 #include "web_contents_adapter_client.h"
 
+#include <QSGAbstractRenderer>
+#include <QSGEngine>
+#include <QSGNode>
+
 #if (QT_VERSION < QT_VERSION_CHECK(5, 4, 0))
 #include <QtWidgets/private/qopenglwidget_p.h>
 #else
 #include <QtWidgets/QOpenGLWidget>
 #endif
 
-QT_BEGIN_NAMESPACE
-class QSGAbstractRenderer;
-class QSGEngine;
-class QSGRootNode;
-class QWindow;
-QT_END_NAMESPACE
-
 class RenderWidgetHostViewQtDelegateWidget : public QOpenGLWidget, public RenderWidgetHostViewQtDelegate {
     Q_OBJECT
 public: