diff --git a/client.cpp b/client.cpp
index 5ee7bd54ff..8022c7eca0 100644
--- a/client.cpp
+++ b/client.cpp
@@ -50,6 +50,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // Qt
 #include <QApplication>
 #include <QDebug>
+#include <QFile>
 #include <QProcess>
 #include <QStandardPaths>
 #include <QScriptEngine>
diff --git a/client.h b/client.h
index 5230b66a35..cf6dbb1dbe 100644
--- a/client.h
+++ b/client.h
@@ -23,7 +23,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define KWIN_CLIENT_H
 
 // kwin
-#include <kdecoration.h>
 #include "options.h"
 #include "rules.h"
 #include "tabgroup.h"
@@ -31,6 +30,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "xcbutils.h"
 // Qt
 #include <QElapsedTimer>
+#include <QFlags>
+#include <QPointer>
 #include <QPixmap>
 #include <QWindow>
 // X
diff --git a/events.cpp b/events.cpp
index da854ef2f6..48ab1c9a17 100644
--- a/events.cpp
+++ b/events.cpp
@@ -48,8 +48,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <QApplication>
 #include <QDebug>
+#include <QHoverEvent>
+#include <QKeyEvent>
+#include <QMouseEvent>
 #include <QStyleHints>
 #include <QWhatsThis>
+#include <QWheelEvent>
 
 #include <kkeyserver.h>
 
diff --git a/input.cpp b/input.cpp
index 7ff1588076..84c10e92cd 100644
--- a/input.cpp
+++ b/input.cpp
@@ -32,6 +32,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #if HAVE_INPUT
 #include "libinput/connection.h"
 #endif
+// Qt
+#include <QKeyEvent>
+#include <QMouseEvent>
 // KDE
 #include <kkeyserver.h>
 // TODO: remove xtest
diff --git a/rules.h b/rules.h
index ff6d9d16f1..eb1a077736 100644
--- a/rules.h
+++ b/rules.h
@@ -24,10 +24,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <netwm_def.h>
 #include <QRect>
+#include <QVector>
 #include <kconfiggroup.h>
 
 #include "placement.h"
-#include <kdecoration.h>
 #include "options.h"
 #include "utils.h"
 
diff --git a/tabbox/tabbox.cpp b/tabbox/tabbox.cpp
index 3060bd6604..03d47ce354 100644
--- a/tabbox/tabbox.cpp
+++ b/tabbox/tabbox.cpp
@@ -45,6 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // Qt
 #include <QAction>
 #include <QDebug>
+#include <QKeyEvent>
 // KDE
 #include <KConfig>
 #include <KConfigGroup>
diff --git a/useractions.cpp b/useractions.cpp
index 2a3b138382..05b7746e68 100644
--- a/useractions.cpp
+++ b/useractions.cpp
@@ -736,7 +736,7 @@ void UserActionsMenu::slotWindowOperation(QAction *action)
         helperDialog(type, c);
     // need to delay performing the window operation as we need to have the
     // user actions menu closed before we destroy the decoration. Otherwise Qt crashes
-    qRegisterMetaType<KDecorationDefines::WindowOperation>();
+    qRegisterMetaType<Options::WindowOperation>();
     QMetaObject::invokeMethod(workspace(), "performWindowOperation",
                               Qt::QueuedConnection,
                               Q_ARG(KWin::Client*, c.data()),