diff --git a/shell/shellcorona.h b/shell/shellcorona.h
--- a/shell/shellcorona.h
+++ b/shell/shellcorona.h
@@ -200,7 +200,6 @@
     void primaryOutputChanged();
 
     void panelContainmentDestroyed(QObject* cont);
-    void desktopContainmentDestroyed(QObject*);
     void showOpenGLNotCompatibleWarning();
     void interactiveConsoleVisibilityChanged(bool visible);
     void handleScreenRemoved(QScreen* screen);
@@ -236,7 +235,6 @@
     KConfigGroup m_lnfDefaultsConfig;
     QList<Plasma::Containment *> m_waitingPanels;
     QHash<QString, QString> m_activityContainmentPlugins;
-    QHash<QString, QSet<Plasma::Containment *> > m_desktopContainments;
     QAction *m_addPanelAction;
     QMenu *m_addPanelsMenu;
     KPackage::Package m_lookAndFeelPackage;
diff --git a/shell/shellcorona.cpp b/shell/shellcorona.cpp
--- a/shell/shellcorona.cpp
+++ b/shell/shellcorona.cpp
@@ -853,7 +853,6 @@
     m_desktopViewforId.clear();
     qDeleteAll(m_panelViews);
     m_panelViews.clear();
-    m_desktopContainments.clear();
     m_waitingPanels.clear();
     m_activityContainmentPlugins.clear();
 
@@ -1233,16 +1232,14 @@
 
 Plasma::Containment *ShellCorona::createContainmentForActivity(const QString& activity, int screenNum)
 {
-    if (m_desktopContainments.contains(activity)) {
-        for (Plasma::Containment *cont : m_desktopContainments.value(activity)) {
-            //in the case of a corrupt config file
-            //with multiple containments with same lastScreen
-            //it can happen two insertContainment happen for
-            //the same screen, leading to the old containment
-            //to be destroyed
-            if (!cont->destroyed() && cont->screen() == screenNum && cont->activity() == activity) {
-                return cont;
-            }
+    for (Plasma::Containment *cont : containmentsForActivity(activity)) {
+        //in the case of a corrupt config file
+        //with multiple containments with same lastScreen
+        //it can happen two insertContainment happen for
+        //the same screen, leading to the old containment
+        //to be destroyed
+        if (!cont->destroyed() && cont->screen() == screenNum) {
+            return cont;
         }
     }
 
@@ -1252,11 +1249,10 @@
         plugin = defaultContainmentPlugin();
     }
 
-    Plasma::Containment *containment = containmentForScreen(screenNum, plugin, QVariantList());
+    Plasma::Containment *containment = containmentForScreen(screenNum, activity, plugin, QVariantList());
     Q_ASSERT(containment);
 
     if (containment) {
-        containment->setActivity(activity);
         insertContainment(activity, screenNum, containment);
     }
 
@@ -1556,10 +1552,8 @@
 void ShellCorona::activityRemoved(const QString &id)
 {
     m_activityContainmentPlugins.remove(id);
-    if (m_desktopContainments.contains(id)) {
-        for (auto cont : m_desktopContainments.value(id)) {
-            cont->destroy();
-        }
+    for (auto cont : containmentsForActivity(id)) {
+        cont->destroy();
     }
 }
 
@@ -1596,7 +1590,8 @@
 
 Plasma::Containment *ShellCorona::setContainmentTypeForScreen(int screen, const QString &plugin)
 {
-    Plasma::Containment *oldContainment = containmentForScreen(screen);
+    //search but not create
+    Plasma::Containment *oldContainment = containmentForScreen(screen, m_activityController->currentActivity(), QString());
 
     //no valid containment in given screen, giving up
     if (!oldContainment) {
@@ -1675,7 +1670,6 @@
     }
     view->setContainment(newContainment);
     newContainment->setActivity(oldContainment->activity());
-    m_desktopContainments.remove(oldContainment->activity());
     insertContainment(oldContainment->activity(), screen, newContainment);
 
     //removing the focus from the item that is going to be destroyed
@@ -1946,7 +1940,8 @@
 void ShellCorona::insertContainment(const QString &activity, int screenNum, Plasma::Containment *containment)
 {
     Plasma::Containment *cont = nullptr;
-    for (Plasma::Containment *c : m_desktopContainments.value(activity)) {
+    auto candidates = containmentsForActivity(activity);
+    for (Plasma::Containment *c : candidates) {
         //using lastScreen() instead of screen() catches also containments of activities that aren't the current one, so not assigned to a screen right now
         if (c->lastScreen() == screenNum) {
             cont = c;
@@ -1957,34 +1952,12 @@
         }
     }
 
-    Q_ASSERT(!m_desktopContainments.value(activity).values().contains(containment));
+    Q_ASSERT(candidates.contains(containment));
+    Q_ASSERT(containment != cont);
 
     if (cont) {
         cont->destroy();
     }
-    m_desktopContainments[activity].insert(containment);
-
-    //when a containment gets deleted update our map of containments
-    connect(containment, SIGNAL(destroyed(QObject*)), this, SLOT(desktopContainmentDestroyed(QObject*)));
-}
-
-void ShellCorona::desktopContainmentDestroyed(QObject *obj)
-{
-    // when QObject::destroyed arrives, ~Plasma::Containment has run,
-    // members of Containment are not accessible anymore,
-    // so keep ugly bookeeping by hand
-    auto containment = static_cast<Plasma::Containment*>(obj);
-    //explicitly specify the range by reference, as we need to remove stuff from the sets
-    for (QSet<Plasma::Containment *> &a : m_desktopContainments) {
-        QMutableSetIterator<Plasma::Containment *> it(a);
-        while (it.hasNext()) {
-            it.next();
-            if (it.value() == containment) {
-                it.remove();
-                return;
-            }
-        }
-    }
 }
 
 void ShellCorona::showOpenGLNotCompatibleWarning()