diff --git a/abstract_client.h b/abstract_client.h
index 12a5afc5f9..81753fb7d3 100644
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -80,6 +80,21 @@ public:
     virtual void maximize(MaximizeMode) = 0;
     virtual bool noBorder() const = 0;
     virtual void setNoBorder(bool set) = 0;
+    virtual void blockActivityUpdates(bool b = true) = 0;
+    virtual QPalette palette() const = 0;
+    virtual bool isResizable() const = 0;
+    virtual bool isMovable() const = 0;
+    virtual bool isMovableAcrossScreens() const = 0;
+    virtual bool isShade() const = 0; // True only for ShadeNormal
+    virtual ShadeMode shadeMode() const = 0; // Prefer isShade()
+    virtual void setShade(bool set) = 0;
+    virtual void setShade(ShadeMode mode) = 0;
+    virtual bool isShadeable() const = 0;
+    virtual bool isMaximizable() const = 0;
+    virtual bool isMinimizable() const = 0;
+    virtual bool userCanSetFullScreen() const = 0;
+    virtual bool userCanSetNoBorder() const = 0;
+    virtual void setOnAllActivities(bool set) = 0;
 
     // TODO: remove boolean trap
     static bool belongToSameApplication(const AbstractClient* c1, const AbstractClient* c2, bool active_hack = false);
diff --git a/client.h b/client.h
index f643faa442..4fed73e22b 100644
--- a/client.h
+++ b/client.h
@@ -362,23 +362,23 @@ public:
 
     virtual QStringList activities() const;
     void setOnActivity(const QString &activity, bool enable);
-    void setOnAllActivities(bool set);
+    void setOnAllActivities(bool set) override;
     void setOnActivities(QStringList newActivitiesList);
     void updateActivities(bool includeTransients);
-    void blockActivityUpdates(bool b = true);
+    void blockActivityUpdates(bool b = true) override;
 
     /// Is not minimized and not hidden. I.e. normally visible on some virtual desktop.
     bool isShown(bool shaded_is_shown) const override;
     bool isHiddenInternal() const; // For compositing
 
-    bool isShade() const; // True only for ShadeNormal
-    ShadeMode shadeMode() const; // Prefer isShade()
-    void setShade(bool set);
-    void setShade(ShadeMode mode);
-    bool isShadeable() const;
+    bool isShade() const override; // True only for ShadeNormal
+    ShadeMode shadeMode() const override; // Prefer isShade()
+    void setShade(bool set) override;
+    void setShade(ShadeMode mode) override;
+    bool isShadeable() const override;
 
     bool isMinimized() const override;
-    bool isMaximizable() const;
+    bool isMaximizable() const override;
     QRect geometryRestore() const;
     MaximizeMode maximizeMode() const override;
 
@@ -395,7 +395,7 @@ public:
 
     Q_DECLARE_FLAGS(QuickTileMode, QuickTileFlag)
     QuickTileMode quickTileMode() const;
-    bool isMinimizable() const;
+    bool isMinimizable() const override;
     void setMaximize(bool vertically, bool horizontally);
     QRect iconGeometry() const;
 
@@ -403,7 +403,7 @@ public:
     bool isFullScreen() const override;
     bool isFullScreenable(bool fullscreen_hack = false) const;
     bool isActiveFullScreen() const;
-    bool userCanSetFullScreen() const;
+    bool userCanSetFullScreen() const override;
     QRect geometryFSRestore() const {
         return geom_fs_restore;    // Only for session saving
     }
@@ -413,7 +413,7 @@ public:
 
     bool noBorder() const override;
     void setNoBorder(bool set) override;
-    bool userCanSetNoBorder() const;
+    bool userCanSetNoBorder() const override;
     void checkNoBorder();
 
     bool skipTaskbar(bool from_outside = false) const;
@@ -442,9 +442,9 @@ public:
     bool wantsTabFocus() const override;
     bool wantsInput() const;
 
-    bool isResizable() const;
-    bool isMovable() const;
-    bool isMovableAcrossScreens() const;
+    bool isResizable() const override;
+    bool isMovable() const override;
+    bool isMovableAcrossScreens() const override;
     bool isCloseable() const override; ///< May be closed by the user (May have a close button)
 
     void takeFocus();
@@ -666,7 +666,7 @@ public:
 
     void cancelFocusOutTimer();
 
-    QPalette palette() const;
+    QPalette palette() const override;
     const Decoration::DecorationPalette *decorationPalette() const;
 
     /**
diff --git a/useractions.cpp b/useractions.cpp
index 55d1efb85d..92f7b57ada 100644
--- a/useractions.cpp
+++ b/useractions.cpp
@@ -92,7 +92,7 @@ UserActionsMenu::UserActionsMenu(QObject *parent)
     , m_closeOperation(NULL)
     , m_removeFromTabGroup(NULL)
     , m_closeTabGroup(NULL)
-    , m_client(QWeakPointer<Client>())
+    , m_client(QWeakPointer<AbstractClient>())
 {
 }
 
@@ -120,7 +120,7 @@ void UserActionsMenu::close()
     m_client.clear();
 }
 
-bool UserActionsMenu::isMenuClient(const Client *c) const
+bool UserActionsMenu::isMenuClient(const AbstractClient *c) const
 {
     if (!c || m_client.isNull()) {
         return false;
@@ -128,7 +128,7 @@ bool UserActionsMenu::isMenuClient(const Client *c) const
     return c == m_client.data();
 }
 
-void UserActionsMenu::show(const QRect &pos, const QWeakPointer<Client> &cl)
+void UserActionsMenu::show(const QRect &pos, const QWeakPointer<AbstractClient> &cl)
 {
     if (!KAuthorized::authorizeKAction(QStringLiteral("kwin_rmb")))
         return;
@@ -165,7 +165,7 @@ void UserActionsMenu::show(const QRect &pos, const QWeakPointer<Client> &cl)
     }
 }
 
-void UserActionsMenu::helperDialog(const QString& message, const QWeakPointer<Client> &c)
+void UserActionsMenu::helperDialog(const QString& message, const QWeakPointer<AbstractClient> &c)
 {
     QStringList args;
     QString type;
@@ -497,12 +497,16 @@ void UserActionsMenu::entabPopupClient(QAction* action)
 {
     if (m_client.isNull() || !action->data().isValid())
         return;
-    Client *other = action->data().value<Client*>();
+    Client *other = dynamic_cast<Client*>(action->data().value<AbstractClient*>());
     if (!Workspace::self()->clientList().contains(other)) // might have been lost betwenn pop-up and selection
         return;
-    m_client.data()->tabBehind(other, true);
+    Client *c = dynamic_cast<Client*>(m_client.data());
+    if (!c) {
+        return;
+    }
+    c->tabBehind(other, true);
     if (options->focusPolicyIsReasonable())
-        Workspace::self()->requestFocus(m_client.data());
+        Workspace::self()->requestFocus(c);
 }
 
 void UserActionsMenu::rebuildTabGroupPopup()
@@ -712,7 +716,7 @@ void UserActionsMenu::slotWindowOperation(QAction *action)
         return;
 
     Options::WindowOperation op = static_cast< Options::WindowOperation >(action->data().toInt());
-    QWeakPointer<Client> c = (!m_client.isNull()) ? m_client : QWeakPointer<Client>(Workspace::self()->activeClient());
+    QWeakPointer<AbstractClient> c = (!m_client.isNull()) ? m_client : QWeakPointer<AbstractClient>(Workspace::self()->activeClient());
     if (c.isNull())
         return;
     QString type;
@@ -746,7 +750,8 @@ void UserActionsMenu::slotSendToDesktop(QAction *action)
     if (!ok) {
         return;
     }
-    if (m_client.isNull())
+    Client *c = dynamic_cast<Client*>(m_client.data());
+    if (c)
         return;
     Workspace *ws = Workspace::self();
     VirtualDesktopManager *vds = VirtualDesktopManager::self();
@@ -758,7 +763,7 @@ void UserActionsMenu::slotSendToDesktop(QAction *action)
         vds->setCount(desk);
     }
 
-    ws->sendClientToDesktop(m_client.data(), desk, false);
+    ws->sendClientToDesktop(c, desk, false);
 }
 
 void UserActionsMenu::slotSendToScreen(QAction *action)
@@ -786,7 +791,12 @@ void UserActionsMenu::slotToggleOnActivity(QAction *action)
         return;
     }
 
-    Activities::self()->toggleClientOnActivity(m_client.data(), activity, false);
+    Client *c = dynamic_cast<Client*>(m_client.data());
+    if (!c) {
+        return;
+    }
+
+    Activities::self()->toggleClientOnActivity(c, activity, false);
     if (m_activityMenu && m_activityMenu->isVisible() && m_activityMenu->actions().count()) {
         const bool isOnAll = m_client.data()->isOnAllActivities();
         m_activityMenu->actions().at(0)->setChecked(isOnAll);
diff --git a/useractions.h b/useractions.h
index 73b07e8621..fc5ce0064d 100644
--- a/useractions.h
+++ b/useractions.h
@@ -30,6 +30,7 @@ class QRect;
 
 namespace KWin
 {
+class AbstractClient;
 class Client;
 
 /**
@@ -78,7 +79,7 @@ public:
      * @param c The Client to compare
      * @returns Whether the Client is the one related to this Menu
      **/
-    bool isMenuClient(const Client *c) const;
+    bool isMenuClient(const AbstractClient *c) const;
     /**
      * Closes the Menu and prepares it for next usage.
      **/
@@ -89,7 +90,7 @@ public:
      * @param pos The position where the menu should be shown.
      * @param client The Client for which the Menu has to be shown.
      **/
-    void show(const QRect &pos, const QWeakPointer<Client> &client);
+    void show(const QRect &pos, const QWeakPointer<AbstractClient> &client);
 
 public Q_SLOTS:
     /**
@@ -199,7 +200,7 @@ private:
      * @param message The message type to be shown
      * @param c The Client for which the dialog should be shown.
      **/
-    void helperDialog(const QString &message, const QWeakPointer<Client> &c);
+    void helperDialog(const QString &message, const QWeakPointer<AbstractClient> &c);
     /**
      * The actual main context menu which is show when the UserActionsMenu is invoked.
      **/
@@ -249,7 +250,7 @@ private:
     /**
      * The Client for which the menu is shown.
      **/
-    QWeakPointer<Client> m_client;
+    QWeakPointer<AbstractClient> m_client;
 };
 
 class ShortcutDialog