diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index c809e772c4..f2d13d47a2 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -44,6 +44,7 @@
 #include "private/qguiapplication_p.h"
 #include "private/qplatformintegrationfactory_qpa_p.h"
 #include "private/qevent_p.h"
+#include "qfont.h"
 
 #if !defined(QT_NO_GLIB)
 #include "qeventdispatcher_glib_qpa_p.h"
diff --git a/src/gui/kernel/qsessionmanager.h b/src/gui/kernel/qsessionmanager.h
index 66ca0b8282..f2163aed38 100644
--- a/src/gui/kernel/qsessionmanager.h
+++ b/src/gui/kernel/qsessionmanager.h
@@ -55,6 +55,8 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(Gui)
 
+class QGuiApplication;
+
 class QSessionManagerPrivate;
 
 class Q_GUI_EXPORT  QSessionManager : public QObject
diff --git a/src/gui/kernel/qsessionmanager_qpa.cpp b/src/gui/kernel/qsessionmanager_qpa.cpp
index 1b4e6a612b..16fca631e0 100644
--- a/src/gui/kernel/qsessionmanager_qpa.cpp
+++ b/src/gui/kernel/qsessionmanager_qpa.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include <qsessionmanager.h>
+#include <qguiapplication.h>
 
 #include <private/qobject_p.h>
 
diff --git a/src/gui/painting/qpaintengine.cpp b/src/gui/painting/qpaintengine.cpp
index 97736263ed..d0ca0bf794 100644
--- a/src/gui/painting/qpaintengine.cpp
+++ b/src/gui/painting/qpaintengine.cpp
@@ -45,6 +45,7 @@
 #include "qbitmap.h"
 #include <qdebug.h>
 #include <qmath.h>
+#include <qguiapplication.h>
 #include <private/qtextengine_p.h>
 #include <qvarlengtharray.h>
 #include <private/qfontengine_p.h>
diff --git a/src/gui/painting/qwindowsurface.cpp b/src/gui/painting/qwindowsurface.cpp
index 13d152175d..d51a2a21c4 100644
--- a/src/gui/painting/qwindowsurface.cpp
+++ b/src/gui/painting/qwindowsurface.cpp
@@ -41,6 +41,7 @@
 
 #include <private/qwindowsurface_p.h>
 #include <qwindow.h>
+#include <qpixmap.h>
 #include <private/qwindow_p.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index 76d858d505..b528637c7b 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -51,6 +51,8 @@
 #include <qvarlengtharray.h>
 #include <qtextcodec.h>
 #include <qthread.h>
+#include <qcoreapplication.h>
+
 #include "qtexthtmlparser_p.h"
 #include "qpainter.h"
 #include "qprinter.h"
diff --git a/src/gui/text/qtexthtmlparser.cpp b/src/gui/text/qtexthtmlparser.cpp
index 0eb0673c69..3eb9897dfa 100644
--- a/src/gui/text/qtexthtmlparser.cpp
+++ b/src/gui/text/qtexthtmlparser.cpp
@@ -46,6 +46,7 @@
 #include <qstack.h>
 #include <qdebug.h>
 #include <qthread.h>
+#include <qcoreapplication.h>
 
 #include "qtextdocument.h"
 #include "qtextformat_p.h"
diff --git a/src/widgets/kernel/qwidgetwindow_qpa_p.h b/src/widgets/kernel/qwidgetwindow_qpa_p.h
index e32a6ed001..67469f6aac 100644
--- a/src/widgets/kernel/qwidgetwindow_qpa_p.h
+++ b/src/widgets/kernel/qwidgetwindow_qpa_p.h
@@ -52,6 +52,9 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(Gui)
 
+class QCloseEvent;
+class QMoveEvent;
+
 class QWidgetWindow : public QWindow
 {
     Q_OBJECT