diff --git a/autotests/integration/effects/scripts/effectsHandler.js b/autotests/integration/effects/scripts/effectsHandler.js
index 5db80636b8..a2e47461e5 100644
--- a/autotests/integration/effects/scripts/effectsHandler.js
+++ b/autotests/integration/effects/scripts/effectsHandler.js
@@ -13,5 +13,5 @@ effects.windowClosed.connect(function(window) {
     sendTestResponse("windowClosed - " + window.caption);
 });
 effects.desktopChanged.connect(function(old, current) {
-    sendTestResponse("desktopChanged - " + old + " " + current);
+    sendTestResponse("desktopChanged - " + old.x11DesktopNumber + " " + current.x11DesktopNumber);
 });
diff --git a/src/effects.cpp b/src/effects.cpp
index c2e43f1af3..0e068e7bd1 100644
--- a/src/effects.cpp
+++ b/src/effects.cpp
@@ -150,11 +150,11 @@ EffectsHandlerImpl::EffectsHandlerImpl(Compositor *compositor, WorkspaceScene *s
         }
     });
     connect(ws, &Workspace::currentDesktopChanged, this, [this](VirtualDesktop *old, Window *window) {
-        const VirtualDesktop *newDesktop = VirtualDesktopManager::self()->currentDesktop();
-        Q_EMIT desktopChanged(old->x11DesktopNumber(), newDesktop->x11DesktopNumber(), window ? window->effectWindow() : nullptr);
+        VirtualDesktop *newDesktop = VirtualDesktopManager::self()->currentDesktop();
+        Q_EMIT desktopChanged(old, newDesktop, window ? window->effectWindow() : nullptr);
     });
     connect(ws, &Workspace::currentDesktopChanging, this, [this](VirtualDesktop *currentDesktop, QPointF offset, KWin::Window *window) {
-        Q_EMIT desktopChanging(currentDesktop->x11DesktopNumber(), offset, window ? window->effectWindow() : nullptr);
+        Q_EMIT desktopChanging(currentDesktop, offset, window ? window->effectWindow() : nullptr);
     });
     connect(ws, &Workspace::currentDesktopChangingCancelled, this, [this]() {
         Q_EMIT desktopChangingCancelled();
@@ -170,12 +170,13 @@ EffectsHandlerImpl::EffectsHandlerImpl(Compositor *compositor, WorkspaceScene *s
         Q_EMIT windowDeleted(d->effectWindow());
     });
     connect(ws->sessionManager(), &SessionManager::stateChanged, this, &KWin::EffectsHandler::sessionStateChanged);
-    connect(vds, &VirtualDesktopManager::countChanged, this, &EffectsHandler::numberDesktopsChanged);
     connect(vds, &VirtualDesktopManager::layoutChanged, this, [this](int width, int height) {
         Q_EMIT desktopGridSizeChanged(QSize(width, height));
         Q_EMIT desktopGridWidthChanged(width);
         Q_EMIT desktopGridHeightChanged(height);
     });
+    connect(vds, &VirtualDesktopManager::desktopCreated, this, &EffectsHandler::desktopAdded);
+    connect(vds, &VirtualDesktopManager::desktopRemoved, this, &EffectsHandler::desktopRemoved);
     connect(Cursors::self()->mouse(), &Cursor::mouseChanged, this, &EffectsHandler::mouseChanged);
     connect(ws, &Workspace::geometryChanged, this, &EffectsHandler::virtualScreenSizeChanged);
     connect(ws, &Workspace::geometryChanged, this, &EffectsHandler::virtualScreenGeometryChanged);
@@ -715,25 +716,12 @@ void EffectsHandlerImpl::moveWindow(EffectWindow *w, const QPoint &pos, bool sna
     }
 }
 
-void EffectsHandlerImpl::windowToDesktops(EffectWindow *w, const QList<uint> &desktopIds)
+void EffectsHandlerImpl::windowToDesktops(EffectWindow *w, const QList<VirtualDesktop *> &desktops)
 {
     auto window = static_cast<EffectWindowImpl *>(w)->window();
     if (!window->isClient() || window->isDesktop() || window->isDock()) {
         return;
     }
-    QList<VirtualDesktop *> desktops;
-    desktops.reserve(desktopIds.count());
-    for (uint x11Id : desktopIds) {
-        if (x11Id > VirtualDesktopManager::self()->count()) {
-            continue;
-        }
-        VirtualDesktop *d = VirtualDesktopManager::self()->desktopForX11Id(x11Id);
-        Q_ASSERT(d);
-        if (desktops.contains(d)) {
-            continue;
-        }
-        desktops << d;
-    }
     window->setDesktops(desktops);
 }
 
@@ -762,26 +750,21 @@ QString EffectsHandlerImpl::currentActivity() const
 #endif
 }
 
-int EffectsHandlerImpl::currentDesktop() const
+VirtualDesktop *EffectsHandlerImpl::currentDesktop() const
 {
-    return VirtualDesktopManager::self()->current();
+    return VirtualDesktopManager::self()->currentDesktop();
 }
 
-int EffectsHandlerImpl::numberOfDesktops() const
+QList<VirtualDesktop *> EffectsHandlerImpl::desktops() const
 {
-    return VirtualDesktopManager::self()->count();
+    return VirtualDesktopManager::self()->desktops();
 }
 
-void EffectsHandlerImpl::setCurrentDesktop(int desktop)
+void EffectsHandlerImpl::setCurrentDesktop(VirtualDesktop *desktop)
 {
     VirtualDesktopManager::self()->setCurrent(desktop);
 }
 
-void EffectsHandlerImpl::setNumberOfDesktops(int desktops)
-{
-    VirtualDesktopManager::self()->setCount(desktops);
-}
-
 QSize EffectsHandlerImpl::desktopGridSize() const
 {
     return VirtualDesktopManager::self()->grid().size();
@@ -807,22 +790,19 @@ int EffectsHandlerImpl::workspaceHeight() const
     return desktopGridHeight() * Workspace::self()->geometry().height();
 }
 
-int EffectsHandlerImpl::desktopAtCoords(QPoint coords) const
+VirtualDesktop *EffectsHandlerImpl::desktopAtCoords(QPoint coords) const
 {
-    if (auto vd = VirtualDesktopManager::self()->grid().at(coords)) {
-        return vd->x11DesktopNumber();
-    }
-    return 0;
+    return VirtualDesktopManager::self()->grid().at(coords);
 }
 
-QPoint EffectsHandlerImpl::desktopGridCoords(int id) const
+QPoint EffectsHandlerImpl::desktopGridCoords(VirtualDesktop *desktop) const
 {
-    return VirtualDesktopManager::self()->grid().gridCoords(id);
+    return VirtualDesktopManager::self()->grid().gridCoords(desktop);
 }
 
-QPoint EffectsHandlerImpl::desktopCoords(int id) const
+QPoint EffectsHandlerImpl::desktopCoords(VirtualDesktop *desktop) const
 {
-    QPoint coords = VirtualDesktopManager::self()->grid().gridCoords(id);
+    QPoint coords = VirtualDesktopManager::self()->grid().gridCoords(desktop);
     if (coords.x() == -1) {
         return QPoint(-1, -1);
     }
@@ -830,30 +810,29 @@ QPoint EffectsHandlerImpl::desktopCoords(int id) const
     return QPoint(coords.x() * displaySize.width(), coords.y() * displaySize.height());
 }
 
-int EffectsHandlerImpl::desktopAbove(int desktop, bool wrap) const
+VirtualDesktop *EffectsHandlerImpl::desktopAbove(VirtualDesktop *desktop, bool wrap) const
 {
     return VirtualDesktopManager::self()->inDirection(desktop, VirtualDesktopManager::Direction::Up, wrap);
 }
 
-int EffectsHandlerImpl::desktopToRight(int desktop, bool wrap) const
+VirtualDesktop *EffectsHandlerImpl::desktopToRight(VirtualDesktop *desktop, bool wrap) const
 {
     return VirtualDesktopManager::self()->inDirection(desktop, VirtualDesktopManager::Direction::Right, wrap);
 }
 
-int EffectsHandlerImpl::desktopBelow(int desktop, bool wrap) const
+VirtualDesktop *EffectsHandlerImpl::desktopBelow(VirtualDesktop *desktop, bool wrap) const
 {
     return VirtualDesktopManager::self()->inDirection(desktop, VirtualDesktopManager::Direction::Down, wrap);
 }
 
-int EffectsHandlerImpl::desktopToLeft(int desktop, bool wrap) const
+VirtualDesktop *EffectsHandlerImpl::desktopToLeft(VirtualDesktop *desktop, bool wrap) const
 {
     return VirtualDesktopManager::self()->inDirection(desktop, VirtualDesktopManager::Direction::Left, wrap);
 }
 
-QString EffectsHandlerImpl::desktopName(int desktop) const
+QString EffectsHandlerImpl::desktopName(VirtualDesktop *desktop) const
 {
-    const VirtualDesktop *vd = VirtualDesktopManager::self()->desktopForX11Id(desktop);
-    return vd ? vd->name() : QString();
+    return desktop->name();
 }
 
 bool EffectsHandlerImpl::optionRollOverDesktops() const
@@ -1014,18 +993,9 @@ Output *EffectsHandlerImpl::activeScreen() const
     return workspace()->activeOutput();
 }
 
-static VirtualDesktop *resolveVirtualDesktop(int desktopId)
+QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const Output *screen, const VirtualDesktop *desktop) const
 {
-    if (desktopId == 0 || desktopId == -1) {
-        return VirtualDesktopManager::self()->currentDesktop();
-    } else {
-        return VirtualDesktopManager::self()->desktopForX11Id(desktopId);
-    }
-}
-
-QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const Output *screen, int desktop) const
-{
-    return Workspace::self()->clientArea(opt, screen, resolveVirtualDesktop(desktop));
+    return Workspace::self()->clientArea(opt, screen, desktop);
 }
 
 QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const EffectWindow *effectWindow) const
@@ -1034,11 +1004,10 @@ QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const EffectWindow *
     return Workspace::self()->clientArea(opt, window);
 }
 
-QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const QPoint &p, int desktop) const
+QRectF EffectsHandlerImpl::clientArea(clientAreaOption opt, const QPoint &p, const VirtualDesktop *desktop) const
 {
     const Output *output = Workspace::self()->outputAt(p);
-    const VirtualDesktop *virtualDesktop = resolveVirtualDesktop(desktop);
-    return Workspace::self()->clientArea(opt, output, virtualDesktop);
+    return Workspace::self()->clientArea(opt, output, desktop);
 }
 
 QRect EffectsHandlerImpl::virtualScreenGeometry() const
@@ -1845,6 +1814,7 @@ WINDOW_HELPER(QIcon, icon, icon)
 WINDOW_HELPER(bool, isSkipSwitcher, skipSwitcher)
 WINDOW_HELPER(bool, decorationHasAlpha, decorationHasAlpha)
 WINDOW_HELPER(bool, isUnresponsive, unresponsive)
+WINDOW_HELPER(QList<VirtualDesktop *>, desktops, desktops)
 
 #undef WINDOW_HELPER
 
@@ -1856,17 +1826,6 @@ qlonglong EffectWindowImpl::windowId() const
     return 0;
 }
 
-QList<uint> EffectWindowImpl::desktops() const
-{
-    const auto desks = m_window->desktops();
-    QList<uint> ids;
-    ids.reserve(desks.count());
-    std::transform(desks.constBegin(), desks.constEnd(), std::back_inserter(ids), [](const VirtualDesktop *vd) {
-        return vd->x11DesktopNumber();
-    });
-    return ids;
-}
-
 QString EffectWindowImpl::windowClass() const
 {
     return m_window->resourceName() + QLatin1Char(' ') + m_window->resourceClass();
diff --git a/src/effects.h b/src/effects.h
index 5c315794f9..056a9ae390 100644
--- a/src/effects.h
+++ b/src/effects.h
@@ -68,23 +68,22 @@ public:
     void setShowingDesktop(bool showing) override;
 
     QString currentActivity() const override;
-    int currentDesktop() const override;
-    int numberOfDesktops() const override;
-    void setCurrentDesktop(int desktop) override;
-    void setNumberOfDesktops(int desktops) override;
+    VirtualDesktop *currentDesktop() const override;
+    QList<VirtualDesktop *> desktops() const override;
+    void setCurrentDesktop(VirtualDesktop *desktop) override;
     QSize desktopGridSize() const override;
     int desktopGridWidth() const override;
     int desktopGridHeight() const override;
     int workspaceWidth() const override;
     int workspaceHeight() const override;
-    int desktopAtCoords(QPoint coords) const override;
-    QPoint desktopGridCoords(int id) const override;
-    QPoint desktopCoords(int id) const override;
-    int desktopAbove(int desktop = 0, bool wrap = true) const override;
-    int desktopToRight(int desktop = 0, bool wrap = true) const override;
-    int desktopBelow(int desktop = 0, bool wrap = true) const override;
-    int desktopToLeft(int desktop = 0, bool wrap = true) const override;
-    QString desktopName(int desktop) const override;
+    VirtualDesktop *desktopAtCoords(QPoint coords) const override;
+    QPoint desktopGridCoords(VirtualDesktop *desktop) const override;
+    QPoint desktopCoords(VirtualDesktop *desktop) const override;
+    VirtualDesktop *desktopAbove(VirtualDesktop *desktop = nullptr, bool wrap = true) const override;
+    VirtualDesktop *desktopToRight(VirtualDesktop *desktop = nullptr, bool wrap = true) const override;
+    VirtualDesktop *desktopBelow(VirtualDesktop *desktop = nullptr, bool wrap = true) const override;
+    VirtualDesktop *desktopToLeft(VirtualDesktop *desktop = nullptr, bool wrap = true) const override;
+    QString desktopName(VirtualDesktop *desktop) const override;
     bool optionRollOverDesktops() const override;
 
     QPointF cursorPos() const override;
@@ -126,9 +125,9 @@ public:
     void addRepaint(const QRegion &r) override;
     void addRepaint(int x, int y, int w, int h) override;
     Output *activeScreen() const override;
-    QRectF clientArea(clientAreaOption, const Output *screen, int desktop) const override;
+    QRectF clientArea(clientAreaOption, const Output *screen, const VirtualDesktop *desktop) const override;
     QRectF clientArea(clientAreaOption, const EffectWindow *c) const override;
-    QRectF clientArea(clientAreaOption, const QPoint &p, int desktop) const override;
+    QRectF clientArea(clientAreaOption, const QPoint &p, const VirtualDesktop *desktop) const override;
     QSize virtualScreenSize() const override;
     QRect virtualScreenGeometry() const override;
     double animationTimeFactor() const override;
@@ -223,7 +222,7 @@ public:
         return registered_atoms.contains(atom);
     }
 
-    void windowToDesktops(EffectWindow *w, const QList<uint> &desktops) override;
+    void windowToDesktops(EffectWindow *w, const QList<VirtualDesktop *> &desktops) override;
 
     /**
      * Finds an effect with the given name.
@@ -341,7 +340,7 @@ public:
     double opacity() const override;
 
     QStringList activities() const override;
-    QList<uint> desktops() const override;
+    QList<VirtualDesktop *> desktops() const override;
     qreal x() const override;
     qreal y() const override;
     qreal width() const override;
diff --git a/src/libkwineffects/kwineffects.cpp b/src/libkwineffects/kwineffects.cpp
index 81b2105265..72f6e6a189 100644
--- a/src/libkwineffects/kwineffects.cpp
+++ b/src/libkwineffects/kwineffects.cpp
@@ -11,6 +11,7 @@
 
 #include "libkwineffects/kwineffects.h"
 #include "core/output.h"
+#include "virtualdesktops.h"
 
 #include "config-kwin.h"
 
@@ -684,10 +685,10 @@ bool EffectWindow::isOnCurrentDesktop() const
     return isOnDesktop(effects->currentDesktop());
 }
 
-bool EffectWindow::isOnDesktop(int d) const
+bool EffectWindow::isOnDesktop(VirtualDesktop *desktop) const
 {
-    const QList<uint> ds = desktops();
-    return ds.isEmpty() || ds.contains(d);
+    const QList<VirtualDesktop *> ds = desktops();
+    return ds.isEmpty() || ds.contains(desktop);
 }
 
 bool EffectWindow::isOnAllDesktops() const
diff --git a/src/libkwineffects/kwineffects.h b/src/libkwineffects/kwineffects.h
index bb69aad355..b429271847 100644
--- a/src/libkwineffects/kwineffects.h
+++ b/src/libkwineffects/kwineffects.h
@@ -82,6 +82,7 @@ class WindowPaintData;
 class ScreenPrePaintData;
 class RenderTarget;
 class RenderViewport;
+class VirtualDesktop;
 
 typedef QPair<QString, Effect *> EffectPair;
 typedef QList<KWin::EffectWindow *> EffectWindowList;
@@ -788,7 +789,7 @@ public:
 class KWIN_EXPORT EffectsHandler : public QObject
 {
     Q_OBJECT
-    Q_PROPERTY(int currentDesktop READ currentDesktop WRITE setCurrentDesktop NOTIFY desktopChanged)
+    Q_PROPERTY(KWin::VirtualDesktop *currentDesktop READ currentDesktop WRITE setCurrentDesktop NOTIFY desktopChanged)
     Q_PROPERTY(QString currentActivity READ currentActivity NOTIFY currentActivityChanged)
     Q_PROPERTY(KWin::EffectWindow *activeWindow READ activeWindow WRITE activateWindow NOTIFY windowActivated)
     Q_PROPERTY(QSize desktopGridSize READ desktopGridSize NOTIFY desktopGridSizeChanged)
@@ -796,10 +797,7 @@ class KWIN_EXPORT EffectsHandler : public QObject
     Q_PROPERTY(int desktopGridHeight READ desktopGridHeight NOTIFY desktopGridHeightChanged)
     Q_PROPERTY(int workspaceWidth READ workspaceWidth)
     Q_PROPERTY(int workspaceHeight READ workspaceHeight)
-    /**
-     * The number of desktops currently used. Minimum number of desktops is 1, maximum 20.
-     */
-    Q_PROPERTY(int desktops READ numberOfDesktops WRITE setNumberOfDesktops NOTIFY numberDesktopsChanged)
+    Q_PROPERTY(QList<KWin::VirtualDesktop *> desktops READ desktops)
     Q_PROPERTY(bool optionRollOverDesktops READ optionRollOverDesktops)
     Q_PROPERTY(KWin::Output *activeScreen READ activeScreen)
     /**
@@ -971,10 +969,8 @@ public:
      * Moves a window to the given desktops
      * On X11, the window will end up on the last window in the list
      * Setting this to an empty list will set the window on all desktops
-     *
-     * @arg desktopIds a list of desktops the window should be placed on. NET::OnAllDesktops is not a valid desktop X11Id
      */
-    Q_SCRIPTABLE virtual void windowToDesktops(KWin::EffectWindow *w, const QList<uint> &desktopIds) = 0;
+    Q_SCRIPTABLE virtual void windowToDesktops(KWin::EffectWindow *w, const QList<KWin::VirtualDesktop *> &desktops) = 0;
 
     Q_SCRIPTABLE virtual void windowToScreen(KWin::EffectWindow *w, Output *screen) = 0;
     virtual void setShowingDesktop(bool showing) = 0;
@@ -986,21 +982,17 @@ public:
     virtual QString currentActivity() const = 0;
     // Desktops
     /**
-     * @returns The ID of the current desktop.
+     * @returns The current desktop.
      */
-    virtual int currentDesktop() const = 0;
+    virtual VirtualDesktop *currentDesktop() const = 0;
     /**
      * @returns Total number of desktops currently in existence.
      */
-    virtual int numberOfDesktops() const = 0;
+    virtual QList<VirtualDesktop *> desktops() const = 0;
     /**
      * Set the current desktop to @a desktop.
      */
-    virtual void setCurrentDesktop(int desktop) = 0;
-    /**
-     * Sets the total number of desktops to @a desktops.
-     */
-    virtual void setNumberOfDesktops(int desktops) = 0;
+    virtual void setCurrentDesktop(KWin::VirtualDesktop *desktop) = 0;
     /**
      * @returns The size of desktop layout in grid units.
      */
@@ -1022,45 +1014,45 @@ public:
      */
     virtual int workspaceHeight() const = 0;
     /**
-     * @returns The ID of the desktop at the point @a coords or 0 if no desktop exists at that
+     * @returns The desktop at the point @a coords or 0 if no desktop exists at that
      * point. @a coords is to be in grid units.
      */
-    virtual int desktopAtCoords(QPoint coords) const = 0;
+    virtual VirtualDesktop *desktopAtCoords(QPoint coords) const = 0;
     /**
-     * @returns The coords of desktop @a id in grid units.
+     * @returns The coords of the specified @a desktop in grid units.
      */
-    virtual QPoint desktopGridCoords(int id) const = 0;
+    virtual QPoint desktopGridCoords(VirtualDesktop *desktop) const = 0;
     /**
-     * @returns The coords of the top-left corner of desktop @a id in pixels.
+     * @returns The coords of the top-left corner of @a desktop in pixels.
      */
-    virtual QPoint desktopCoords(int id) const = 0;
+    virtual QPoint desktopCoords(VirtualDesktop *desktop) const = 0;
     /**
-     * @returns The ID of the desktop above desktop @a id. Wraps around to the bottom of
+     * @returns The desktop above the given @a desktop. Wraps around to the bottom of
      * the layout if @a wrap is set. If @a id is not set use the current one.
      */
-    Q_SCRIPTABLE virtual int desktopAbove(int desktop = 0, bool wrap = true) const = 0;
+    Q_SCRIPTABLE virtual KWin::VirtualDesktop *desktopAbove(KWin::VirtualDesktop *desktop = nullptr, bool wrap = true) const = 0;
     /**
-     * @returns The ID of the desktop to the right of desktop @a id. Wraps around to the
+     * @returns The desktop to the right of the given @a desktop. Wraps around to the
      * left of the layout if @a wrap is set. If @a id is not set use the current one.
      */
-    Q_SCRIPTABLE virtual int desktopToRight(int desktop = 0, bool wrap = true) const = 0;
+    Q_SCRIPTABLE virtual KWin::VirtualDesktop *desktopToRight(KWin::VirtualDesktop *desktop = nullptr, bool wrap = true) const = 0;
     /**
-     * @returns The ID of the desktop below desktop @a id. Wraps around to the top of the
+     * @returns The desktop below the given @a desktop. Wraps around to the top of the
      * layout if @a wrap is set. If @a id is not set use the current one.
      */
-    Q_SCRIPTABLE virtual int desktopBelow(int desktop = 0, bool wrap = true) const = 0;
+    Q_SCRIPTABLE virtual KWin::VirtualDesktop *desktopBelow(KWin::VirtualDesktop *desktop = nullptr, bool wrap = true) const = 0;
     /**
-     * @returns The ID of the desktop to the left of desktop @a id. Wraps around to the
+     * @returns The desktop to the left of the given @a desktop. Wraps around to the
      * right of the layout if @a wrap is set. If @a id is not set use the current one.
      */
-    Q_SCRIPTABLE virtual int desktopToLeft(int desktop = 0, bool wrap = true) const = 0;
-    Q_SCRIPTABLE virtual QString desktopName(int desktop) const = 0;
+    Q_SCRIPTABLE virtual KWin::VirtualDesktop *desktopToLeft(KWin::VirtualDesktop *desktop = nullptr, bool wrap = true) const = 0;
+    Q_SCRIPTABLE virtual QString desktopName(KWin::VirtualDesktop *desktop) const = 0;
     virtual bool optionRollOverDesktops() const = 0;
 
     virtual Output *activeScreen() const = 0; // Xinerama
-    virtual QRectF clientArea(clientAreaOption, const Output *screen, int desktop) const = 0;
+    virtual QRectF clientArea(clientAreaOption, const Output *screen, const VirtualDesktop *desktop) const = 0;
     virtual QRectF clientArea(clientAreaOption, const EffectWindow *c) const = 0;
-    virtual QRectF clientArea(clientAreaOption, const QPoint &p, int desktop) const = 0;
+    virtual QRectF clientArea(clientAreaOption, const QPoint &p, const VirtualDesktop *desktop) const = 0;
 
     /**
      * The bounding size of all screens combined. Overlapping areas
@@ -1417,7 +1409,7 @@ Q_SIGNALS:
      * @param with The window which is taken over to the new desktop, can be NULL
      * @since 4.9
      */
-    void desktopChanged(int oldDesktop, int newDesktop, KWin::EffectWindow *with);
+    void desktopChanged(KWin::VirtualDesktop *oldDesktop, KWin::VirtualDesktop *newDesktop, KWin::EffectWindow *with);
 
     /**
      * Signal emmitted while desktop is changing for animation.
@@ -1426,8 +1418,10 @@ Q_SIGNALS:
      * offset.x() = .6 means 60% of the way to the desktop to the right.
      * Positive Values means Up and Right.
      */
-    void desktopChanging(uint currentDesktop, QPointF offset, KWin::EffectWindow *with);
+    void desktopChanging(KWin::VirtualDesktop *currentDesktop, QPointF offset, KWin::EffectWindow *with);
     void desktopChangingCancelled();
+    void desktopAdded(KWin::VirtualDesktop *desktop);
+    void desktopRemoved(KWin::VirtualDesktop *desktop);
 
     /**
      * Emitted when the virtual desktop grid layout changes
@@ -1447,13 +1441,6 @@ Q_SIGNALS:
      * @since 5.25
      */
     void desktopGridHeightChanged(int height);
-    /**
-     * Signal emitted when the number of currently existing desktops is changed.
-     * @param old The previous number of desktops in used.
-     * @see EffectsHandler::numberOfDesktops.
-     * @since 4.7
-     */
-    void numberDesktopsChanged(uint old);
     /**
      * Signal emitted when the desktop showing ("dashboard") state changed
      * The desktop is risen to the keepAbove layer, you may want to elevate
@@ -1716,7 +1703,7 @@ class KWIN_EXPORT EffectWindow : public QObject
     Q_PROPERTY(qreal width READ width)
     Q_PROPERTY(qreal x READ x)
     Q_PROPERTY(qreal y READ y)
-    Q_PROPERTY(QList<uint> desktops READ desktops)
+    Q_PROPERTY(QList<KWin::VirtualDesktop *> desktops READ desktops)
     Q_PROPERTY(bool onAllDesktops READ isOnAllDesktops)
     Q_PROPERTY(bool onCurrentDesktop READ isOnCurrentDesktop)
     Q_PROPERTY(QRectF rect READ rect)
@@ -2026,7 +2013,7 @@ public:
     bool isOnAllActivities() const;
     virtual QStringList activities() const = 0;
 
-    Q_SCRIPTABLE bool isOnDesktop(int d) const;
+    Q_SCRIPTABLE bool isOnDesktop(KWin::VirtualDesktop *desktop) const;
     bool isOnCurrentDesktop() const;
     bool isOnAllDesktops() const;
     /**
@@ -2034,7 +2021,7 @@ public:
      * a length of 1, on Wayland can be any subset.
      * If the list is empty it means the window is on all desktops
      */
-    virtual QList<uint> desktops() const = 0;
+    virtual QList<KWin::VirtualDesktop *> desktops() const = 0;
 
     virtual qreal x() const = 0;
     virtual qreal y() const = 0;
diff --git a/src/plugins/overview/overvieweffect.cpp b/src/plugins/overview/overvieweffect.cpp
index 33fc0df2d5..23318f6685 100644
--- a/src/plugins/overview/overvieweffect.cpp
+++ b/src/plugins/overview/overvieweffect.cpp
@@ -101,11 +101,11 @@ OverviewEffect::OverviewEffect()
     connect(m_gridState, &EffectTogglableState::inProgressChanged, this, &OverviewEffect::gridGestureInProgressChanged);
     connect(m_gridState, &EffectTogglableState::partialActivationFactorChanged, this, &OverviewEffect::gridPartialActivationFactorChanged);
 
-    connect(effects, &EffectsHandler::desktopChanging, this, [this](uint old, QPointF desktopOffset, EffectWindow *with) {
+    connect(effects, &EffectsHandler::desktopChanging, this, [this](VirtualDesktop *old, QPointF desktopOffset, EffectWindow *with) {
         m_desktopOffset = desktopOffset;
         Q_EMIT desktopOffsetChanged();
     });
-    connect(effects, &EffectsHandler::desktopChanged, this, [this](int old, int current, EffectWindow *with) {
+    connect(effects, &EffectsHandler::desktopChanged, this, [this](VirtualDesktop *old, VirtualDesktop *current, EffectWindow *with) {
         m_desktopOffset = QPointF(0, 0);
         Q_EMIT desktopOffsetChanged();
     });
@@ -362,7 +362,7 @@ void OverviewEffect::grabbedKeyboardEvent(QKeyEvent *keyEvent)
     QuickSceneEffect::grabbedKeyboardEvent(keyEvent);
 }
 
-void OverviewEffect::swapDesktops(uint from, uint to)
+void OverviewEffect::swapDesktops(VirtualDesktop *from, VirtualDesktop *to)
 {
     QList<EffectWindow *> fromList;
     QList<EffectWindow *> toList;
diff --git a/src/plugins/overview/overvieweffect.h b/src/plugins/overview/overvieweffect.h
index 176003e8b9..ab6907db64 100644
--- a/src/plugins/overview/overvieweffect.h
+++ b/src/plugins/overview/overvieweffect.h
@@ -59,7 +59,7 @@ public:
     void reconfigure(ReconfigureFlags flags) override;
     void grabbedKeyboardEvent(QKeyEvent *keyEvent) override;
 
-    Q_INVOKABLE void swapDesktops(uint from, uint to);
+    Q_INVOKABLE void swapDesktops(KWin::VirtualDesktop *from, KWin::VirtualDesktop *to);
 
 Q_SIGNALS:
     void animationDurationChanged();
diff --git a/src/plugins/overview/qml/main.qml b/src/plugins/overview/qml/main.qml
index 1feccd97aa..88129fe924 100644
--- a/src/plugins/overview/qml/main.qml
+++ b/src/plugins/overview/qml/main.qml
@@ -485,7 +485,7 @@ FocusScope {
                                 drop.action = Qt.IgnoreAction;
                                 return;
                             }
-                            effect.swapDesktops(drag.source.desktop.x11DesktopNumber, desktop.x11DesktopNumber);
+                            effect.swapDesktops(drag.source.desktop, desktop);
                         } else {
                             // dragging a KWin::Window
                             if (drag.source.desktops.length === 0 || drag.source.desktops.indexOf(mainBackground.desktop) !== -1) {
diff --git a/src/plugins/slide/slide.cpp b/src/plugins/slide/slide.cpp
index e58405e909..9ea1482eeb 100644
--- a/src/plugins/slide/slide.cpp
+++ b/src/plugins/slide/slide.cpp
@@ -36,7 +36,9 @@ SlideEffect::SlideEffect()
             this, &SlideEffect::windowAdded);
     connect(effects, &EffectsHandler::windowDeleted,
             this, &SlideEffect::windowDeleted);
-    connect(effects, &EffectsHandler::numberDesktopsChanged,
+    connect(effects, &EffectsHandler::desktopAdded,
+            this, &SlideEffect::finishedSwitching);
+    connect(effects, &EffectsHandler::desktopRemoved,
             this, &SlideEffect::finishedSwitching);
     connect(effects, &EffectsHandler::screenAdded,
             this, &SlideEffect::finishedSwitching);
@@ -106,6 +108,7 @@ void SlideEffect::prePaintScreen(ScreenPrePaintData &data, std::chrono::millisec
         m_currentPosition.setY(m_motionY.position() / virtualSpaceSize.height());
     }
 
+    const QList<VirtualDesktop *> desktops = effects->desktops();
     const int w = effects->desktopGridWidth();
     const int h = effects->desktopGridHeight();
 
@@ -113,20 +116,21 @@ void SlideEffect::prePaintScreen(ScreenPrePaintData &data, std::chrono::millisec
     m_paintCtx.visibleDesktops.clear();
     m_paintCtx.visibleDesktops.reserve(4); // 4 - maximum number of visible desktops
     bool includedX = false, includedY = false;
-    for (int i = 1; i <= effects->numberOfDesktops(); i++) {
-        if (effects->desktopGridCoords(i).x() % w == (int)(m_currentPosition.x()) % w) {
+    for (VirtualDesktop *desktop : desktops) {
+        const QPoint coords = effects->desktopGridCoords(desktop);
+        if (coords.x() % w == (int)(m_currentPosition.x()) % w) {
             includedX = true;
-        } else if (effects->desktopGridCoords(i).x() % w == ((int)(m_currentPosition.x()) + 1) % w) {
+        } else if (coords.x() % w == ((int)(m_currentPosition.x()) + 1) % w) {
             includedX = true;
         }
-        if (effects->desktopGridCoords(i).y() % h == (int)(m_currentPosition.y()) % h) {
+        if (coords.y() % h == (int)(m_currentPosition.y()) % h) {
             includedY = true;
-        } else if (effects->desktopGridCoords(i).y() % h == ((int)(m_currentPosition.y()) + 1) % h) {
+        } else if (coords.y() % h == ((int)(m_currentPosition.y()) + 1) % h) {
             includedY = true;
         }
 
         if (includedX && includedY) {
-            m_paintCtx.visibleDesktops << i;
+            m_paintCtx.visibleDesktops << desktop;
         }
     }
 
@@ -177,8 +181,8 @@ bool SlideEffect::willBePainted(const EffectWindow *w) const
     if (w == m_movingWindow) {
         return true;
     }
-    for (const int &id : std::as_const(m_paintCtx.visibleDesktops)) {
-        if (w->isOnDesktop(id)) {
+    for (VirtualDesktop *desktop : std::as_const(m_paintCtx.visibleDesktops)) {
+        if (w->isOnDesktop(desktop)) {
             return true;
         }
     }
@@ -214,7 +218,7 @@ void SlideEffect::paintWindow(const RenderTarget &renderTarget, const RenderView
 
     const auto screens = effects->screens();
 
-    for (int desktop : std::as_const(m_paintCtx.visibleDesktops)) {
+    for (VirtualDesktop *desktop : std::as_const(m_paintCtx.visibleDesktops)) {
         if (!w->isOnDesktop(desktop)) {
             continue;
         }
@@ -283,7 +287,7 @@ bool SlideEffect::shouldElevate(const EffectWindow *w) const
  * Called AFTER the gesture is released.
  * Sets up animation to round off to the new current desktop.
  */
-void SlideEffect::startAnimation(int old, int current, EffectWindow *movingWindow)
+void SlideEffect::startAnimation(VirtualDesktop *old, VirtualDesktop *current, EffectWindow *movingWindow)
 {
     if (m_state == State::Inactive) {
         prepareSwitching();
@@ -351,7 +355,7 @@ void SlideEffect::finishedSwitching()
     m_currentPosition = effects->desktopGridCoords(effects->currentDesktop());
 }
 
-void SlideEffect::desktopChanged(int old, int current, EffectWindow *with)
+void SlideEffect::desktopChanged(VirtualDesktop *old, VirtualDesktop *current, EffectWindow *with)
 {
     if (effects->hasActiveFullScreenEffect() && effects->activeFullScreenEffect() != this) {
         m_currentPosition = effects->desktopGridCoords(effects->currentDesktop());
@@ -361,7 +365,7 @@ void SlideEffect::desktopChanged(int old, int current, EffectWindow *with)
     startAnimation(old, current, with);
 }
 
-void SlideEffect::desktopChanging(uint old, QPointF desktopOffset, EffectWindow *with)
+void SlideEffect::desktopChanging(VirtualDesktop *old, QPointF desktopOffset, EffectWindow *with)
 {
     if (effects->hasActiveFullScreenEffect() && effects->activeFullScreenEffect() != this) {
         return;
diff --git a/src/plugins/slide/slide.h b/src/plugins/slide/slide.h
index 795b83b7e1..99626e0d1e 100644
--- a/src/plugins/slide/slide.h
+++ b/src/plugins/slide/slide.h
@@ -73,8 +73,8 @@ public:
     bool slideBackground() const;
 
 private Q_SLOTS:
-    void desktopChanged(int old, int current, EffectWindow *with);
-    void desktopChanging(uint old, QPointF desktopOffset, EffectWindow *with);
+    void desktopChanged(VirtualDesktop *old, VirtualDesktop *current, EffectWindow *with);
+    void desktopChanging(VirtualDesktop *old, QPointF desktopOffset, EffectWindow *with);
     void desktopChangingCancelled();
     void windowAdded(EffectWindow *w);
     void windowDeleted(EffectWindow *w);
@@ -89,7 +89,7 @@ private:
     QPointF forcePositivePosition(QPointF p) const;
     void optimizePath(); // Find the best path to target desktop
 
-    void startAnimation(int old, int current, EffectWindow *movingWindow = nullptr);
+    void startAnimation(VirtualDesktop *old, VirtualDesktop *current, EffectWindow *movingWindow = nullptr);
     void prepareSwitching();
     void finishedSwitching();
 
@@ -120,7 +120,7 @@ private:
     struct
     {
         bool wrap;
-        QList<int> visibleDesktops;
+        QList<VirtualDesktop *> visibleDesktops;
     } m_paintCtx;
 
     struct WindowData