diff --git a/composite.h b/composite.h
--- a/composite.h
+++ b/composite.h
@@ -23,8 +23,6 @@
 #define KWIN_COMPOSITE_H
 // KWin
 #include <kwinglobals.h>
-// KDE
-#include <KSelectionOwner>
 // Qt
 #include <QObject>
 #include <QElapsedTimer>
@@ -35,20 +33,9 @@
 namespace KWin {
 
 class Client;
+class CompositorSelectionOwner;
 class Scene;
 
-class CompositorSelectionOwner : public KSelectionOwner
-{
-    Q_OBJECT
-public:
-    CompositorSelectionOwner(const char *selection);
-private:
-    friend class Compositor;
-    bool owning;
-private Q_SLOTS:
-    void looseOwnership();
-};
-
 class KWIN_EXPORT Compositor : public QObject {
     Q_OBJECT
 public:
@@ -216,7 +203,7 @@
     SuspendReasons m_suspended;
 
     QBasicTimer compositeTimer;
-    CompositorSelectionOwner* cm_selection;
+    CompositorSelectionOwner *m_selectionOwner;
     QTimer m_releaseSelectionTimer;
     QList<xcb_atom_t> m_unusedSupportProperties;
     QTimer m_unusedSupportPropertyTimer;
diff --git a/composite.cpp b/composite.cpp
--- a/composite.cpp
+++ b/composite.cpp
@@ -46,7 +46,7 @@
 #include <KPluginLoader>
 #include <KPluginMetaData>
 #include <KNotification>
-#include <KSelectionWatcher>
+#include <KSelectionOwner>
 
 #include <QDateTime>
 #include <QFutureWatcher>
@@ -69,15 +69,26 @@
 
 extern int currentRefreshRate();
 
-CompositorSelectionOwner::CompositorSelectionOwner(const char *selection) : KSelectionOwner(selection, connection(), rootWindow()), owning(false)
+class CompositorSelectionOwner : public KSelectionOwner
 {
-    connect (this, SIGNAL(lostOwnership()), SLOT(looseOwnership()));
-}
-
-void CompositorSelectionOwner::looseOwnership()
-{
-    owning = false;
-}
+    Q_OBJECT
+public:
+    CompositorSelectionOwner(const char *selection)
+        : KSelectionOwner(selection, connection(), rootWindow())
+        , m_owning(false)
+    {
+        connect (this, &CompositorSelectionOwner::lostOwnership,
+                 this, [this]() { m_owning = false; });
+    }
+    bool owning() const {
+        return m_owning;
+    }
+    void setOwning(bool own) {
+        m_owning = own;
+    }
+private:
+    bool m_owning;
+};
 
 KWIN_SINGLETON_FACTORY_VARIABLE(Compositor, s_compositor)
 
@@ -87,7 +98,7 @@
 Compositor::Compositor(QObject* workspace)
     : QObject(workspace)
     , m_suspended(options->isUseCompositing() ? NoReasonSuspend : UserSuspend)
-    , cm_selection(NULL)
+    , m_selectionOwner(NULL)
     , vBlankInterval(0)
     , fpsInterval(0)
     , m_xrrRefreshRate(0)
@@ -133,8 +144,8 @@
     );
     connect(kwinApp(), &Application::x11ConnectionAboutToBeDestroyed, this,
         [this] {
-            delete cm_selection;
-            cm_selection = nullptr;
+            delete m_selectionOwner;
+            m_selectionOwner = nullptr;
         }
     );
 
@@ -150,7 +161,7 @@
     emit aboutToDestroy();
     finish();
     deleteUnusedSupportProperties();
-    delete cm_selection;
+    delete m_selectionOwner;
     s_compositor = NULL;
 }
 
@@ -249,9 +260,9 @@
         delete m_scene;
         m_scene = NULL;
         m_starting = false;
-        if (cm_selection) {
-            cm_selection->owning = false;
-            cm_selection->release();
+        if (m_selectionOwner) {
+            m_selectionOwner->setOwning(false);
+            m_selectionOwner->release();
         }
         if (!supportedCompositors.contains(NoCompositing)) {
             qCCritical(KWIN_CORE) << "The used windowing system requires compositing";
@@ -280,28 +291,28 @@
 
 void Compositor::claimCompositorSelection()
 {
-    if (!cm_selection) {
+    if (!m_selectionOwner) {
         char selection_name[ 100 ];
         sprintf(selection_name, "_NET_WM_CM_S%d", Application::x11ScreenNumber());
-        cm_selection = new CompositorSelectionOwner(selection_name);
-        connect(cm_selection, SIGNAL(lostOwnership()), SLOT(finish()));
+        m_selectionOwner = new CompositorSelectionOwner(selection_name);
+        connect(m_selectionOwner, &CompositorSelectionOwner::lostOwnership, this, &Compositor::finish);
     }
 
-    if (!cm_selection) // no X11 yet
+    if (!m_selectionOwner) // no X11 yet
         return;
 
-    if (!cm_selection->owning) {
-        cm_selection->claim(true);   // force claiming
-        cm_selection->owning = true;
+    if (!m_selectionOwner->owning()) {
+        m_selectionOwner->claim(true);   // force claiming
+        m_selectionOwner->setOwning(true);
     }
 }
 
 void Compositor::setupX11Support()
 {
     auto c = kwinApp()->x11Connection();
     if (!c) {
-        delete cm_selection;
-        cm_selection = nullptr;
+        delete m_selectionOwner;
+        m_selectionOwner = nullptr;
         return;
     }
     claimCompositorSelection();
@@ -446,9 +457,9 @@
         return;
     }
     qCDebug(KWIN_CORE) << "Releasing compositor selection";
-    if (cm_selection) {
-        cm_selection->owning = false;
-        cm_selection->release();
+    if (m_selectionOwner) {
+        m_selectionOwner->setOwning(false);
+        m_selectionOwner->release();
     }
 }
 
@@ -920,3 +931,6 @@
 }
 
 } // namespace
+
+// included for CompositorSelectionOwner
+#include "composite.moc"
diff --git a/main.h b/main.h
--- a/main.h
+++ b/main.h
@@ -25,8 +25,6 @@
 #include <kwinglobals.h>
 #include <config-kwin.h>
 
-#include <KSelectionWatcher>
-#include <KSelectionOwner>
 #include <KSharedConfig>
 // Qt
 #include <QApplication>
diff --git a/main_x11.h b/main_x11.h
--- a/main_x11.h
+++ b/main_x11.h
@@ -24,20 +24,7 @@
 namespace KWin
 {
 
-class KWinSelectionOwner
-    : public KSelectionOwner
-{
-    Q_OBJECT
-public:
-    explicit KWinSelectionOwner(int screen);
-protected:
-    virtual bool genericReply(xcb_atom_t target, xcb_atom_t property, xcb_window_t requestor);
-    virtual void replyTargets(xcb_atom_t property, xcb_window_t requestor);
-    virtual void getAtoms();
-private:
-    xcb_atom_t make_selection_atom(int screen);
-    static xcb_atom_t xa_version;
-};
+class KWinSelectionOwner;
 
 class ApplicationX11 : public Application
 {
diff --git a/main_x11.cpp b/main_x11.cpp
--- a/main_x11.cpp
+++ b/main_x11.cpp
@@ -20,21 +20,22 @@
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #include "main_x11.h"
+
 #include <config-kwin.h>
-// kwin
+
 #include "platform.h"
 #include "sm.h"
 #include "workspace.h"
 #include "xcbutils.h"
 
-// KDE
 #include <KConfigGroup>
 #include <KCrash>
 #include <KLocalizedString>
 #include <KPluginLoader>
 #include <KPluginMetaData>
+#include <KSelectionOwner>
 #include <KQuickAddons/QtQuickSettings>
-// Qt
+
 #include <qplatformdefs.h>
 #include <QComboBox>
 #include <QCommandLineParser>
@@ -63,8 +64,6 @@
     QApplication::exit();
 }
 
-
-
 class AlternativeWMDialog : public QDialog
 {
 public:
@@ -111,66 +110,64 @@
     QComboBox* wmList;
 };
 
-//************************************
-// KWinSelectionOwner
-//************************************
-
-KWinSelectionOwner::KWinSelectionOwner(int screen_P)
-    : KSelectionOwner(make_selection_atom(screen_P), screen_P)
+class KWinSelectionOwner : public KSelectionOwner
 {
-}
+    Q_OBJECT
+public:
+    explicit KWinSelectionOwner(int screen)
+        : KSelectionOwner(make_selection_atom(screen), screen)
+    {
+    }
 
-xcb_atom_t KWinSelectionOwner::make_selection_atom(int screen_P)
-{
-    if (screen_P < 0)
-        screen_P = QX11Info::appScreen();
-    QByteArray screen(QByteArrayLiteral("WM_S"));
-    screen.append(QByteArray::number(screen_P));
-    ScopedCPointer<xcb_intern_atom_reply_t> atom(xcb_intern_atom_reply(
-        connection(),
-        xcb_intern_atom_unchecked(connection(), false, screen.length(), screen.constData()),
-        nullptr));
-    if (atom.isNull()) {
-        return XCB_ATOM_NONE;
+private:
+    bool genericReply(xcb_atom_t target_P, xcb_atom_t property_P, xcb_window_t requestor_P) override {
+        if (target_P == xa_version) {
+            int32_t version[] = { 2, 0 };
+            xcb_change_property(connection(), XCB_PROP_MODE_REPLACE, requestor_P,
+                                property_P, XCB_ATOM_INTEGER, 32, 2, version);
+        } else
+            return KSelectionOwner::genericReply(target_P, property_P, requestor_P);
+        return true;
     }
-    return atom->atom;
-}
 
-void KWinSelectionOwner::getAtoms()
-{
-    KSelectionOwner::getAtoms();
-    if (xa_version == XCB_ATOM_NONE) {
-        const QByteArray name(QByteArrayLiteral("VERSION"));
+    void replyTargets(xcb_atom_t property_P, xcb_window_t requestor_P) override {
+        KSelectionOwner::replyTargets(property_P, requestor_P);
+        xcb_atom_t atoms[ 1 ] = { xa_version };
+        // PropModeAppend !
+        xcb_change_property(connection(), XCB_PROP_MODE_APPEND, requestor_P,
+                            property_P, XCB_ATOM_ATOM, 32, 1, atoms);
+    }
+
+    void getAtoms() override {
+        KSelectionOwner::getAtoms();
+        if (xa_version == XCB_ATOM_NONE) {
+            const QByteArray name(QByteArrayLiteral("VERSION"));
+            ScopedCPointer<xcb_intern_atom_reply_t> atom(xcb_intern_atom_reply(
+                connection(),
+                xcb_intern_atom_unchecked(connection(), false, name.length(), name.constData()),
+                nullptr));
+            if (!atom.isNull()) {
+                xa_version = atom->atom;
+            }
+        }
+    }
+
+    xcb_atom_t make_selection_atom(int screen_P) {
+        if (screen_P < 0)
+            screen_P = QX11Info::appScreen();
+        QByteArray screen(QByteArrayLiteral("WM_S"));
+        screen.append(QByteArray::number(screen_P));
         ScopedCPointer<xcb_intern_atom_reply_t> atom(xcb_intern_atom_reply(
             connection(),
-            xcb_intern_atom_unchecked(connection(), false, name.length(), name.constData()),
+            xcb_intern_atom_unchecked(connection(), false, screen.length(), screen.constData()),
             nullptr));
-        if (!atom.isNull()) {
-            xa_version = atom->atom;
+        if (atom.isNull()) {
+            return XCB_ATOM_NONE;
         }
+        return atom->atom;
     }
-}
-
-void KWinSelectionOwner::replyTargets(xcb_atom_t property_P, xcb_window_t requestor_P)
-{
-    KSelectionOwner::replyTargets(property_P, requestor_P);
-    xcb_atom_t atoms[ 1 ] = { xa_version };
-    // PropModeAppend !
-    xcb_change_property(connection(), XCB_PROP_MODE_APPEND, requestor_P,
-                        property_P, XCB_ATOM_ATOM, 32, 1, atoms);
-}
-
-bool KWinSelectionOwner::genericReply(xcb_atom_t target_P, xcb_atom_t property_P, xcb_window_t requestor_P)
-{
-    if (target_P == xa_version) {
-        int32_t version[] = { 2, 0 };
-        xcb_change_property(connection(), XCB_PROP_MODE_REPLACE, requestor_P,
-                            property_P, XCB_ATOM_INTEGER, 32, 2, version);
-    } else
-        return KSelectionOwner::genericReply(target_P, property_P, requestor_P);
-    return true;
-}
-
+    static xcb_atom_t xa_version;
+};
 xcb_atom_t KWinSelectionOwner::xa_version = XCB_ATOM_NONE;
 
 //************************************
@@ -475,3 +472,5 @@
                       // listens for events and talks to it, so it needs to be created.
     return a.exec();
 }
+
+#include "main_x11.moc"
diff --git a/xwl/xwayland.cpp b/xwl/xwayland.cpp
--- a/xwl/xwayland.cpp
+++ b/xwl/xwayland.cpp
@@ -26,6 +26,7 @@
 #include "utils.h"
 
 #include <KLocalizedString>
+#include <KSelectionOwner>
 
 #include "xcbutils.h"