diff --git a/kcms/desktoptheme/kcm.h b/kcms/desktoptheme/kcm.h
--- a/kcms/desktoptheme/kcm.h
+++ b/kcms/desktoptheme/kcm.h
@@ -104,7 +104,6 @@
     QStandardItemModel *m_model;
     QString m_selectedPlugin;
     QStringList m_pendingRemoval;
-    Plasma::Theme *m_defaultTheme;
     QHash<QString, Plasma::Theme*> m_themes;
     bool m_haveThemeExplorerInstalled;
 
diff --git a/kcms/desktoptheme/kcm.cpp b/kcms/desktoptheme/kcm.cpp
--- a/kcms/desktoptheme/kcm.cpp
+++ b/kcms/desktoptheme/kcm.cpp
@@ -49,7 +49,6 @@
 
 KCMDesktopTheme::KCMDesktopTheme(QObject *parent, const QVariantList &args)
     : KQuickAddons::ConfigModule(parent, args)
-    , m_defaultTheme(new Plasma::Theme(this))
     , m_haveThemeExplorerInstalled(false)
 {
     qmlRegisterType<QStandardItemModel>();
@@ -74,7 +73,6 @@
 
 KCMDesktopTheme::~KCMDesktopTheme()
 {
-    delete m_defaultTheme;
 }
 
 QStandardItemModel *KCMDesktopTheme::desktopThemeModel() const
@@ -282,17 +280,21 @@
     m_model->sort(0 /*column*/);
 
     KConfigGroup cg(KSharedConfig::openConfig(QStringLiteral("plasmarc")), "Theme");
-    setSelectedPlugin(cg.readEntry("name", m_defaultTheme->themeName()));
+    setSelectedPlugin(cg.readEntry("name", QStringLiteral("default")));
 
     emit selectedPluginIndexChanged();
 
     updateNeedsSave();
 }
 
 void KCMDesktopTheme::save()
 {
-    if (m_defaultTheme->themeName() != m_selectedPlugin) {
-        m_defaultTheme->setThemeName(m_selectedPlugin);
+    KConfigGroup cg(KSharedConfig::openConfig(QStringLiteral("plasmarc")), "Theme");
+    const auto currentTheme = cg.readEntry("name", QStringLiteral("default"));
+    if (currentTheme != m_selectedPlugin) {
+        cg.writeEntry("name", m_selectedPlugin);
+        cg.sync();
+        Plasma::Theme().setThemeName(m_selectedPlugin);
     }
 
     processPendingDeletions();
@@ -322,8 +324,10 @@
 
 void KCMDesktopTheme::updateNeedsSave()
 {
+    KConfigGroup cg(KSharedConfig::openConfig(QStringLiteral("plasmarc")), "Theme");
+    const auto currentTheme = cg.readEntry("name", QStringLiteral("default"));
     setNeedsSave(!m_model->match(m_model->index(0, 0), PendingDeletionRole, true).isEmpty()
-                    || m_selectedPlugin != m_defaultTheme->themeName());
+                    || m_selectedPlugin != currentTheme);
 }
 
 void KCMDesktopTheme::processPendingDeletions()