diff --git a/autotests/kstartupinfo_unittest.cpp b/autotests/kstartupinfo_unittest.cpp
--- a/autotests/kstartupinfo_unittest.cpp
+++ b/autotests/kstartupinfo_unittest.cpp
@@ -316,12 +316,14 @@
         QCOMPARE(KStartupInfo::startupId(), str);
     }
 
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
     {
         QWidget widget;
         const QByteArray str = "somefancyidwhichisrandom_kstartupinfo_unittest_3";
         KStartupInfo::setNewStartupId(&widget, str); // deprecated
         QCOMPARE(KStartupInfo::startupId(), str);
     }
+#endif
 }
 
 QTEST_MAIN(KStartupInfo_UnitTest)
diff --git a/autotests/kwindowsystemx11test.cpp b/autotests/kwindowsystemx11test.cpp
--- a/autotests/kwindowsystemx11test.cpp
+++ b/autotests/kwindowsystemx11test.cpp
@@ -276,11 +276,12 @@
     QTest::qWait(200);
 
     QSignalSpy propertiesChangedSpy(KWindowSystem::self(), SIGNAL(windowChanged(WId,NET::Properties,NET::Properties2)));
-    QSignalSpy propertyChangedSpy(KWindowSystem::self(), SIGNAL(windowChanged(WId,uint)));
-    QSignalSpy windowChangedSpy(KWindowSystem::self(), SIGNAL(windowChanged(WId)));
-
     QVERIFY(propertiesChangedSpy.isValid());
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
+    QSignalSpy propertyChangedSpy(KWindowSystem::self(), SIGNAL(windowChanged(WId,uint)));
     QVERIFY(propertyChangedSpy.isValid());
+#endif
+    QSignalSpy windowChangedSpy(KWindowSystem::self(), SIGNAL(windowChanged(WId)));
     QVERIFY(windowChangedSpy.isValid());
 
     widget.setWindowTitle(QStringLiteral("bar"));
@@ -308,6 +309,7 @@
     }
     QVERIFY(gotWMName);
 
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
     gotWMName = false;
     QCOMPARE(propertyChangedSpy.isEmpty(), false);
     for (auto it = propertyChangedSpy.constBegin(); it != propertyChangedSpy.constEnd(); ++it) {
@@ -325,6 +327,7 @@
         }
     }
     QVERIFY(gotWMName);
+#endif
 
     QCOMPARE(windowChangedSpy.isEmpty(), false);
     bool gotWindow = false;
diff --git a/autotests/kxmessages_unittest.cpp b/autotests/kxmessages_unittest.cpp
--- a/autotests/kxmessages_unittest.cpp
+++ b/autotests/kxmessages_unittest.cpp
@@ -27,7 +27,9 @@
 public:
     enum BroadcastType {
         BroadcastMessageObject,
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
         BroadcastStaticDisplay,
+#endif
         BroadcastStaticConnection
     };
     enum ReceiverType {
@@ -56,10 +58,14 @@
     QTest::addColumn<KXMessages_UnitTest::ReceiverType>("receiverType");
 
     QTest::newRow("object")     << BroadcastMessageObject << ReceiverTypeDefault;
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
     QTest::newRow("display")    << BroadcastStaticDisplay << ReceiverTypeDefault;
+#endif
     QTest::newRow("connection") << BroadcastStaticConnection << ReceiverTypeDefault;
     QTest::newRow("object/xcb")     << BroadcastMessageObject << ReceiverTypeConnection;
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
     QTest::newRow("display/xcb")    << BroadcastStaticDisplay << ReceiverTypeConnection;
+#endif
     QTest::newRow("connection/xcb") << BroadcastStaticConnection << ReceiverTypeConnection;
 }
 
@@ -91,9 +97,11 @@
         case KXMessages_UnitTest::BroadcastMessageObject:
             m_msgs.broadcastMessage(type, message);
             break;
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
         case KXMessages_UnitTest::BroadcastStaticDisplay:
             QVERIFY(KXMessages::broadcastMessageX(QX11Info::display(), type.constData(), message));
             break;
+#endif
         case KXMessages_UnitTest::BroadcastStaticConnection:
             QVERIFY(KXMessages::broadcastMessageX(QX11Info::connection(), type.constData(), message, QX11Info::appScreen()));
             break;
diff --git a/src/kstartupinfo.cpp b/src/kstartupinfo.cpp
--- a/src/kstartupinfo.cpp
+++ b/src/kstartupinfo.cpp
@@ -38,7 +38,9 @@
 #include "netwm_def.h"
 #include "kwindowsystem_debug.h"
 
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
 #include <QWidget>
+#endif
 #include <QDateTime>
 
 #include <config-kwindowsystem.h> // KWINDOWSYSTEM_HAVE_X11
@@ -62,7 +64,7 @@
 #include <qx11info_x11.h>
 #include <netwm.h>
 #endif
-#include <QApplication>
+#include <QCoreApplication>
 #include <QDebug>
 #include <signal.h>
 #include <qstandardpaths.h>
@@ -714,11 +716,7 @@
     }
 #if KWINDOWSYSTEM_HAVE_X11
     if (QX11Info::isPlatformX11() && !qEnvironmentVariableIsEmpty("DISPLAY")) {  // don't rely on QX11Info::display()
-        Display *disp = XOpenDisplay(nullptr);
-        if (disp != nullptr) {
-            KStartupInfo::sendFinishX(disp, id);
-            XCloseDisplay(disp);
-        }
+        KStartupInfo::sendFinish(id);
     }
 #endif
 }
@@ -775,13 +773,15 @@
     }
 }
 
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
 void KStartupInfo::setNewStartupId(QWidget *window, const QByteArray &startup_id)
 {
     // Set the WA_NativeWindow attribute to force the creation of the QWindow.
     // Without this QWidget::windowHandle() returns 0.
     window->setAttribute(Qt::WA_NativeWindow, true);
     setNewStartupId(window->window()->windowHandle(), startup_id);
 }
+#endif
 
 void KStartupInfo::setNewStartupId(QWindow *window, const QByteArray &startup_id)
 {
diff --git a/src/kwindowsystem.cpp b/src/kwindowsystem.cpp
--- a/src/kwindowsystem.cpp
+++ b/src/kwindowsystem.cpp
@@ -28,7 +28,9 @@
 #include <QMetaMethod>
 #include <QPixmap>
 #include <QPluginLoader>
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
 #include <QWidget>
+#endif
 #include <QWindow>
 #if KWINDOWSYSTEM_HAVE_X11
 #include <QX11Info>
diff --git a/src/platforms/xcb/kwindowsystem.cpp b/src/platforms/xcb/kwindowsystem.cpp
--- a/src/platforms/xcb/kwindowsystem.cpp
+++ b/src/platforms/xcb/kwindowsystem.cpp
@@ -233,35 +233,36 @@
         xcb_window_t old_active_window = activeWindow();
         int old_number_of_desktops = numberOfDesktops();
         bool old_showing_desktop = showingDesktop();
-        unsigned long m[ 5 ];
-        NETRootInfo::event(ev, m, 5);
+        NET::Properties props;
+        NET::Properties2 props2;
+        NETRootInfo::event(ev, &props, &props2);
 
-        if ((m[ PROTOCOLS ] & CurrentDesktop) && currentDesktop() != old_current_desktop) {
+        if ((props & CurrentDesktop) && currentDesktop() != old_current_desktop) {
             emit s_q->currentDesktopChanged(currentDesktop());
         }
-        if ((m[ PROTOCOLS ] & DesktopViewport) && mapViewport() && currentDesktop() != old_current_desktop) {
+        if ((props & DesktopViewport) && mapViewport() && currentDesktop() != old_current_desktop) {
             emit s_q->currentDesktopChanged(currentDesktop());
         }
-        if ((m[ PROTOCOLS ] & ActiveWindow) && activeWindow() != old_active_window) {
+        if ((props & ActiveWindow) && activeWindow() != old_active_window) {
             emit s_q->activeWindowChanged(activeWindow());
         }
-        if (m[ PROTOCOLS ] & DesktopNames) {
+        if (props & DesktopNames) {
             emit s_q->desktopNamesChanged();
         }
-        if ((m[ PROTOCOLS ] & NumberOfDesktops) && numberOfDesktops() != old_number_of_desktops) {
+        if ((props & NumberOfDesktops) && numberOfDesktops() != old_number_of_desktops) {
             emit s_q->numberOfDesktopsChanged(numberOfDesktops());
         }
-        if ((m[ PROTOCOLS ] & DesktopGeometry) && mapViewport() && numberOfDesktops() != old_number_of_desktops) {
+        if ((props & DesktopGeometry) && mapViewport() && numberOfDesktops() != old_number_of_desktops) {
             emit s_q->numberOfDesktopsChanged(numberOfDesktops());
         }
-        if (m[ PROTOCOLS ] & WorkArea) {
+        if (props & WorkArea) {
             emit s_q->workAreaChanged();
         }
-        if (m[ PROTOCOLS ] & ClientListStacking) {
+        if (props & ClientListStacking) {
             updateStackingOrder();
             emit s_q->stackingOrderChanged();
         }
-        if ((m[ PROTOCOLS2 ] & WM2ShowingDesktop) && showingDesktop() != old_showing_desktop) {
+        if ((props2 & WM2ShowingDesktop) && showingDesktop() != old_showing_desktop) {
             emit s_q->showingDesktopChanged(showingDesktop());
         }
     } else if (windows.contains(eventWindow)) {
diff --git a/tests/setmainwindowtest.cpp b/tests/setmainwindowtest.cpp
--- a/tests/setmainwindowtest.cpp
+++ b/tests/setmainwindowtest.cpp
@@ -67,7 +67,8 @@
     layout->addWidget(new QLabel("Test Dialog.\nYou should not be able to bring the parent window on top of me."));
 
     // Show it
-    KWindowSystem::setMainWindow(dialog, id);
+    dialog->setAttribute(Qt::WA_NativeWindow, true);
+    KWindowSystem::setMainWindow(dialog->windowHandle(), id);
     dialog->exec();
 
     m_label->setText(QString());