diff --git a/client.h b/client.h
index 50ca579b3c..cc1201f167 100644
--- a/client.h
+++ b/client.h
@@ -24,7 +24,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <config-X11.h>
 
-#include <qframe.h>
+#include <QFrame>
 #include <QPixmap>
 #include <netwm.h>
 #include <kdebug.h>
diff --git a/clients/modernsystem/modernsys.cpp b/clients/modernsystem/modernsys.cpp
index 7b3e3b0a19..fb42420ea2 100644
--- a/clients/modernsystem/modernsys.cpp
+++ b/clients/modernsystem/modernsys.cpp
@@ -24,7 +24,7 @@
 #include <kglobal.h>
 #include <klocale.h>
 #include <QLayout>
-#include <qdrawutil.h>
+#include <QtGui/qdrawutil.h>
 //Added by qt3to4:
 #include <QPixmap>
 #include <QPaintEvent>
diff --git a/clients/oxygen/oxygenclient.cpp b/clients/oxygen/oxygenclient.cpp
index 7d5fcfc4f8..f0329f5a88 100644
--- a/clients/oxygen/oxygenclient.cpp
+++ b/clients/oxygen/oxygenclient.cpp
@@ -33,11 +33,11 @@
 #include <KDebug>
 #include <KColorUtils>
 
-#include <qbitmap.h>
-#include <qlabel.h>
-#include <qlayout.h>
-#include <qpainter.h>
-#include <qtooltip.h>
+#include <QBitmap>
+#include <QLabel>
+#include <QLayout>
+#include <QPainter>
+#include <QToolTip>
 //Added by qt3to4:
 #include <QBoxLayout>
 #include <QGridLayout>
diff --git a/clients/plastik/plastikclient.cpp b/clients/plastik/plastikclient.cpp
index 8fb894784c..53a6fc43db 100644
--- a/clients/plastik/plastikclient.cpp
+++ b/clients/plastik/plastikclient.cpp
@@ -30,7 +30,7 @@
 #include <QLayout>
 #include <QPainter>
 #include <QPixmap>
-#include <qdesktopwidget.h>
+#include <QDesktopWidget>
 
 #include "plastikclient.h"
 #include "plastikbutton.h"
diff --git a/clients/redmond/redmond.cpp b/clients/redmond/redmond.cpp
index c0904dd17d..7ac5dad37c 100644
--- a/clients/redmond/redmond.cpp
+++ b/clients/redmond/redmond.cpp
@@ -26,7 +26,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "redmond.h"
 
-#include <qdrawutil.h>
+#include <QtGui/qdrawutil.h>
 #include <QDateTime>
 //Added by qt3to4:
 #include <QPixmap>
diff --git a/effects/desktopgrid.cpp b/effects/desktopgrid.cpp
index 6d9dd01ade..8bddc442c0 100644
--- a/effects/desktopgrid.cpp
+++ b/effects/desktopgrid.cpp
@@ -27,7 +27,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <klocale.h>
 #include <kconfiggroup.h>
 #include <netwm_def.h>
-#include <qevent.h>
+#include <QEvent>
+#include <QMouseEvent>
 
 namespace KWin
 {
diff --git a/effects/desktopgrid.h b/effects/desktopgrid.h
index dade2a3633..9f5b4fb7f2 100644
--- a/effects/desktopgrid.h
+++ b/effects/desktopgrid.h
@@ -22,7 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define KWIN_DESKTOPGRID_H
 
 #include <kwineffects.h>
-#include <qobject.h>
+#include <QObject>
 
 namespace KWin
 {
diff --git a/effects/presentwindows.cpp b/effects/presentwindows.cpp
index 811f3b7808..3665d1b361 100644
--- a/effects/presentwindows.cpp
+++ b/effects/presentwindows.cpp
@@ -28,7 +28,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kdebug.h>
 
 #include <QMouseEvent>
-#include <qpainter.h>
+#include <QPainter>
 
 #include <math.h>
 #include <assert.h>
diff --git a/effects/showfps.h b/effects/showfps.h
index 64de1a2606..e5742b1100 100644
--- a/effects/showfps.h
+++ b/effects/showfps.h
@@ -23,7 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <kwineffects.h>
 
-#include <qdatetime.h>
+#include <QDateTime>
 
 namespace KWin
 {
diff --git a/kcmkwin/kwinoptions/windows.cpp b/kcmkwin/kwinoptions/windows.cpp
index 4e8417e032..6dd535f1fc 100644
--- a/kcmkwin/kwinoptions/windows.cpp
+++ b/kcmkwin/kwinoptions/windows.cpp
@@ -33,14 +33,16 @@
 #include <QRadioButton>
 #include <QLabel>
 #include <QComboBox>
-#include <qdesktopwidget.h>
+#include <QDesktopWidget>
 //Added by qt3to4:
 #include <QGridLayout>
 #include <QHBoxLayout>
 #include <QBoxLayout>
 #include <QVBoxLayout>
-#include <kmessagebox.h>
+#include <QTabWidget>
+#include <QtDBus/QtDBus>
 
+#include <kmessagebox.h>
 #include <klocale.h>
 #include <kcolorbutton.h>
 #include <kconfig.h>
@@ -49,8 +51,6 @@
 #include <kdialog.h>
 #include <kglobal.h>
 #include <kprocess.h>
-#include <QTabWidget>
-#include <QtDBus/QtDBus>
 
 #include <X11/X.h>
 #include <X11/Xlib.h>
diff --git a/popupinfo.cpp b/popupinfo.cpp
index c3fa41c31d..883b5375f4 100644
--- a/popupinfo.cpp
+++ b/popupinfo.cpp
@@ -35,7 +35,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kdebug.h>
 #include <klocale.h>
 #include <QApplication>
-#include <qdesktopwidget.h>
+#include <QDesktopWidget>
 #include <kstringhandler.h>
 #include <kglobalsettings.h>
 #include <QX11Info>
diff --git a/scene.h b/scene.h
index ff0b51028e..a5b0c70d6f 100644
--- a/scene.h
+++ b/scene.h
@@ -21,7 +21,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef KWIN_SCENE_H
 #define KWIN_SCENE_H
 
-#include <qdatetime.h>
+#include <QDateTime>
 
 #include "toplevel.h"
 #include "utils.h"
diff --git a/sm.cpp b/sm.cpp
index 772d625934..95c51b8e44 100644
--- a/sm.cpp
+++ b/sm.cpp
@@ -31,7 +31,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "workspace.h"
 #include "client.h"
 #include <QSocketNotifier>
-#include <qsessionmanager.h>
+#include <QSessionManager>
 #include <kdebug.h>
 
 namespace KWin
diff --git a/sm.h b/sm.h
index 4150b196d4..b93c2b6240 100644
--- a/sm.h
+++ b/sm.h
@@ -27,7 +27,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <ksessionmanager.h>
 #include <X11/SM/SMlib.h>
 #include <netwm_def.h>
-#include <qrect.h>
+#include <QRect>
 
 class QSocketNotifier;
 
diff --git a/tabbox.cpp b/tabbox.cpp
index b964101819..416f140e03 100644
--- a/tabbox.cpp
+++ b/tabbox.cpp
@@ -34,7 +34,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kconfig.h>
 #include <klocale.h>
 #include <QApplication>
-#include <qdesktopwidget.h>
+#include <QDesktopWidget>
 #include <QAction>
 #include <stdarg.h>
 #include <kdebug.h>
diff --git a/toplevel.h b/toplevel.h
index 6df7e8fac9..9091b6a8e1 100644
--- a/toplevel.h
+++ b/toplevel.h
@@ -24,7 +24,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <config-X11.h>
 
 #include <assert.h>
-#include <qobject.h>
+#include <QObject>
 #include <kdecoration.h>
 #include <kdebug.h>
 
diff --git a/workspace.h b/workspace.h
index 25ee03296f..0fa62776ff 100644
--- a/workspace.h
+++ b/workspace.h
@@ -28,7 +28,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QCursor>
 #include <netwm.h>
 #include <kxmessages.h>
-#include <qdatetime.h>
+#include <QDateTime>
 #include <kmanagerselection.h>
 
 #include "utils.h"