diff --git a/qt5/style/qtcurve.h b/qt5/style/qtcurve.h
--- a/qt5/style/qtcurve.h
+++ b/qt5/style/qtcurve.h
@@ -522,6 +522,9 @@
                                       const QWidget *widget) const;
 
 private:
+    class DBusHelper;
+    DBusHelper *m_dBusHelper;
+
     mutable Options opts;
     QColor m_highlightCols[TOTAL_SHADES + 1],
         m_backgroundCols[TOTAL_SHADES + 1],
@@ -564,14 +567,12 @@
     mutable QList<int> m_mdiButtons[2]; // 0=left, 1=right
     mutable int m_titlebarHeight;
 
-    QDBusInterface *m_dBus;
     ShadowHelper *m_shadowHelper;
     mutable QScrollBar *m_sViewSBar;
     mutable QMap<QWidget*, QSet<QWidget*> > m_sViewContainers;
     WindowManager *m_windowManager;
     BlurHelper *m_blurHelper;
     ShortcutHandler *m_shortcutHandler;
-    bool m_dbusConnected;
 #ifdef QTC_QT5_ENABLE_KDE
     KSharedConfigPtr m_configFile;
     KSharedConfigPtr m_kdeGlobals;
diff --git a/qt5/style/qtcurve.cpp b/qt5/style/qtcurve.cpp
--- a/qt5/style/qtcurve.cpp
+++ b/qt5/style/qtcurve.cpp
@@ -101,6 +101,26 @@
 
 namespace QtCurve {
 
+class Style::DBusHelper {
+public:
+    DBusHelper()
+        : m_dBus(0)
+        , m_dbusConnected(false)
+    {}
+    ~DBusHelper()
+    {
+        if (m_dBus) {
+            m_dBus->disconnect();
+            m_dBus->deleteLater();
+            m_dBus = 0;
+        }
+    }
+
+    std::once_flag m_aboutToQuitInit;
+    QDBusInterface *m_dBus;
+    bool m_dbusConnected;
+};
+
 static inline void setPainterPen(QPainter *p, const QColor &col, const qreal width=1.0)
 {
     p->setPen(QPen(col, width));
@@ -321,6 +341,7 @@
 #endif
 
 Style::Style() :
+    m_dBusHelper(new DBusHelper()),
     m_popupMenuCols(0L),
     m_sliderCols(0L),
     m_defBtnCols(0L),
@@ -343,13 +364,11 @@
     m_progressBarAnimateTimer(0),
     m_animateStep(0),
     m_titlebarHeight(0),
-    m_dBus(0),
     m_shadowHelper(new ShadowHelper(this)),
     m_sViewSBar(0L),
     m_windowManager(new WindowManager(this)),
     m_blurHelper(new BlurHelper(this)),
-    m_shortcutHandler(new ShortcutHandler(this)),
-    m_dbusConnected(false)
+    m_shortcutHandler(new ShortcutHandler(this))
 {
     const char *env = getenv(QTCURVE_PREVIEW_CONFIG);
 #ifdef QTC_QT5_ENABLE_KDE
@@ -394,6 +413,23 @@
 #ifdef QTC_QT5_ENABLE_KDE
             connect(KWindowSystem::self(), &KWindowSystem::compositingChanged, this, &Style::compositingToggled);
 #endif
+            // prepare the cleanup handler
+            if (QCoreApplication::instance()) {
+                std::call_once(m_dBusHelper->m_aboutToQuitInit, [this] {
+                    connect(QCoreApplication::instance(), &QCoreApplication::aboutToQuit, this, [this] () {
+                            // disconnect from the session DBus. We're no longer interested in the
+                            // information it might send when the app we're serving is shutting down.
+                            disconnectDBus();
+                            // Stop listening to select signals. We shouldn't stop emitting signals
+                            // (like QObject::destroyed) but we can reduce the likelihood that pending
+                            // signals will be sent to us post-mortem.
+#ifdef QTC_QT5_ENABLE_KDE
+                            disconnect(KWindowSystem::self(), &KWindowSystem::compositingChanged,
+                                       this, &Style::compositingToggled);
+#endif
+                        } );
+                } );
+            }
         }
     }
 
@@ -663,14 +699,11 @@
 
 void Style::connectDBus()
 {
-    if (m_dbusConnected)
+    if (m_dBusHelper->m_dbusConnected)
         return;
     auto bus = QDBusConnection::sessionBus();
     if (bus.isConnected()) {
-        m_dbusConnected = true;
-        if (QCoreApplication::instance()) {
-            connect(QCoreApplication::instance(), &QCoreApplication::aboutToQuit, this, &Style::disconnectDBus);
-        }
+        m_dBusHelper->m_dbusConnected = true;
         bus.connect(QString(), "/KGlobalSettings", "org.kde.KGlobalSettings",
                     "notifyChange", this, SLOT(kdeGlobalSettingsChange(int, int)));
 #ifndef QTC_QT5_ENABLE_KDE
@@ -699,12 +732,15 @@
 
 void Style::disconnectDBus()
 {
-    if (!m_dbusConnected)
+    if (!m_dBusHelper->m_dbusConnected)
         return;
-    m_dbusConnected = false;
     auto bus = QDBusConnection::sessionBus();
+    if (!bus.isConnected())
+        return;
+    m_dBusHelper->m_dbusConnected = false;
     if (getenv("QTCURVE_DEBUG")) {
         qWarning() << Q_FUNC_INFO << this << "Disconnecting from" << bus.name() << "/" << bus.baseService();
+        dumpObjectInfo();
     }
     bus.disconnect(QString(), "/KGlobalSettings", "org.kde.KGlobalSettings",
                    "notifyChange",
@@ -739,9 +775,7 @@
         m_plugin->m_styleInstances.removeAll(this);
     }
     freeColors();
-    if (m_dBus) {
-        delete m_dBus;
-    }
+    delete m_dBusHelper;
 }
 
 void Style::freeColor(QSet<QColor *> &freedColors, QColor **cols)
@@ -4467,22 +4501,22 @@
         if (oldSize != size) {
             w->setProperty(constMenuSizeProperty, size);
             qtcX11SetMenubarSize(wid, size);
-            if(!m_dBus)
-                m_dBus = new QDBusInterface("org.kde.kwin", "/QtCurve",
+            if(!m_dBusHelper->m_dBus)
+                m_dBusHelper->m_dBus = new QDBusInterface("org.kde.kwin", "/QtCurve",
                                              "org.kde.QtCurve");
-            m_dBus->call(QDBus::NoBlock, "menuBarSize",
+            m_dBusHelper->m_dBus->call(QDBus::NoBlock, "menuBarSize",
                           (unsigned int)wid, (int)size);
         }
     }
 }
 
 void Style::emitStatusBarState(QStatusBar *sb)
 {
     if (opts.statusbarHiding & HIDE_KWIN) {
-        if (!m_dBus)
-            m_dBus = new QDBusInterface("org.kde.kwin", "/QtCurve",
+        if (!m_dBusHelper->m_dBus)
+            m_dBusHelper->m_dBus = new QDBusInterface("org.kde.kwin", "/QtCurve",
                                         "org.kde.QtCurve");
-        m_dBus->call(QDBus::NoBlock, "statusBarState",
+        m_dBusHelper->m_dBus->call(QDBus::NoBlock, "statusBarState",
                      (unsigned int)qtcGetWid(sb->window()),
                      sb->isVisible());
     }
diff --git a/qt5/style/qtcurve_plugin.cpp b/qt5/style/qtcurve_plugin.cpp
--- a/qt5/style/qtcurve_plugin.cpp
+++ b/qt5/style/qtcurve_plugin.cpp
@@ -129,6 +129,11 @@
     if (key.toLower() == "qtcurve") {
         qtc = new Style;
         qtc->m_plugin = this;
+        // keep track of all style instances we allocate, for instance
+        // for KLineEdit widgets which apparently insist on overriding
+        // certain things (cf. KLineEditStyle). We want to be able to
+        // delete those instances as properly and as early as
+        // possible during the global destruction phase.
         m_styleInstances << qtc;
     } else {
         qtc = nullptr;
@@ -151,12 +156,14 @@
     qtcInfo("Deleting QtCurve plugin (%p)\n", this);
     if (!m_styleInstances.isEmpty()) {
         qtcWarn("there remain(s) %d Style instance(s)\n", m_styleInstances.count());
-        QList<Style*>::Iterator it = m_styleInstances.begin();
-        while (it != m_styleInstances.end()) {
-            Style *that = *it;
-            it = m_styleInstances.erase(it);
+        foreach (Style *that, m_styleInstances) {
+            // don't let ~Style() touch m_styleInstances from here.
+            that->m_plugin = nullptr;
+            // each instance should already have disconnected from the D-Bus
+            // and disconnected from receiving select signals.
             delete that;
         }
+        m_styleInstances.clear();
     }
     if (firstPlInstance == this) {
         firstPlInstance = nullptr;