diff --git a/autotests/testkwaylandconfig.cpp b/autotests/testkwaylandconfig.cpp
--- a/autotests/testkwaylandconfig.cpp
+++ b/autotests/testkwaylandconfig.cpp
@@ -53,6 +53,7 @@
     void testRotationChange_data();
     void testScaleChange();
     void testModeChange();
+    void testApplyOnPending();
 
 private:
 
@@ -265,6 +266,60 @@
     QCOMPARE(configSpy.count(), 1);
 }
 
+void TestKWaylandConfig::testApplyOnPending()
+{
+    auto op = new GetConfigOperation();
+    QVERIFY(op->exec());
+    auto config = op->config();
+    QVERIFY(config);
+
+    auto op2 = new GetConfigOperation();
+    QVERIFY(op2->exec());
+    auto config2 = op2->config();
+    QVERIFY(config2);
+
+    KScreen::ConfigMonitor *monitor = KScreen::ConfigMonitor::instance();
+    monitor->addConfig(config);
+    QSignalSpy configSpy(monitor, &KScreen::ConfigMonitor::configurationChanged);
+
+    auto output = config->outputs()[1]; // is this id stable enough?
+
+    QCOMPARE(output->scale(), 1.0);
+    output->setScale(2);
+
+    QSignalSpy serverSpy(m_server, &WaylandTestServer::configChanged);
+    QSignalSpy serverReceivedSpy(m_server, &WaylandTestServer::configReceived);
+
+    m_server->suspendChanges(true);
+
+    new SetConfigOperation(config, this);
+
+    /* Apply next config */
+
+    auto output2 = config2->outputs()[2]; // is this id stable enough?
+    QCOMPARE(output2->scale(), 2.0);
+    output2->setScale(3);
+
+    new SetConfigOperation(config2, this);
+
+    QVERIFY(serverReceivedSpy.wait());
+    QCOMPARE(serverReceivedSpy.count(), 1);
+    m_server->suspendChanges(false);
+
+    QVERIFY(configSpy.wait());
+    // check if the server changed
+    QCOMPARE(serverSpy.count(), 1);
+    QCOMPARE(configSpy.count(), 1);
+    QCOMPARE(output->scale(), 2);
+    QCOMPARE(output2->scale(), 3);
+
+    QVERIFY(configSpy.wait());
+    // check if the server changed
+    QCOMPARE(serverSpy.count(), 2);
+    QCOMPARE(configSpy.count(), 2);
+    QCOMPARE(output2->scale(), 3);
+}
+
 
 QTEST_GUILESS_MAIN(TestKWaylandConfig)
 
diff --git a/backends/kwayland/waylandconfig.h b/backends/kwayland/waylandconfig.h
--- a/backends/kwayland/waylandconfig.h
+++ b/backends/kwayland/waylandconfig.h
@@ -92,6 +92,7 @@
     void initConnection();
     void blockSignals();
     void unblockSignals();
+    void tryPendingConfig();
 
     KWayland::Client::ConnectionThread *m_connection;
     KWayland::Client::EventQueue *m_queue;
@@ -111,6 +112,7 @@
     QEventLoop m_syncLoop;
     int m_newOutputId;
     KScreen::ConfigPtr m_kscreenConfig;
+    KScreen::ConfigPtr m_kscreenPendingConfig;
     WaylandScreen *m_screen;
 
 };
diff --git a/backends/kwayland/waylandconfig.cpp b/backends/kwayland/waylandconfig.cpp
--- a/backends/kwayland/waylandconfig.cpp
+++ b/backends/kwayland/waylandconfig.cpp
@@ -48,6 +48,7 @@
     , m_blockSignals(true)
     , m_newOutputId(0)
     , m_kscreenConfig(nullptr)
+    , m_kscreenPendingConfig(nullptr)
     , m_screen(new WaylandScreen(this))
 {
     connect(this, &WaylandConfig::initialized, &m_syncLoop, &QEventLoop::quit);
@@ -274,13 +275,28 @@
     return m_outputMap;
 }
 
+void WaylandConfig::tryPendingConfig()
+{
+    if (!m_kscreenPendingConfig) {
+        return;
+    }
+    applyConfig(m_kscreenPendingConfig);
+    m_kscreenPendingConfig = nullptr;
+}
+
 void WaylandConfig::applyConfig(const KScreen::ConfigPtr &newConfig)
 {
     using namespace KWayland::Client;
     // Create a new configuration object
     auto wlOutputConfiguration = m_outputManagement->createConfiguration();
     bool changed = false;
 
+    if (m_blockSignals) {
+        /* Last apply still pending, remember new changes and apply afterwards */
+        m_kscreenPendingConfig = newConfig;
+        return;
+    }
+
     Q_FOREACH (auto output, newConfig->outputs()) {
         auto o_old = m_outputMap[output->id()];
         auto device = o_old->outputDevice();
@@ -334,11 +350,13 @@
         wlOutputConfiguration->deleteLater();
         unblockSignals();
         Q_EMIT configChanged(toKScreenConfig());
+        tryPendingConfig();
     });
     connect(wlOutputConfiguration, &OutputConfiguration::failed, this, [this, wlOutputConfiguration] {
         wlOutputConfiguration->deleteLater();
         unblockSignals();
         Q_EMIT configChanged(toKScreenConfig());
+        tryPendingConfig();
     });
     blockSignals();
     // Now ask the compositor to apply the changes
diff --git a/tests/kwayland/waylandtestserver.h b/tests/kwayland/waylandtestserver.h
--- a/tests/kwayland/waylandtestserver.h
+++ b/tests/kwayland/waylandtestserver.h
@@ -59,11 +59,14 @@
 
     int outputCount() const;
 
+    void suspendChanges(bool suspend);
+
 Q_SIGNALS:
     void outputsChanged();
 
     void started();
 
+    void configReceived();
     void configChanged();
 
 private Q_SLOTS:
@@ -76,6 +79,8 @@
     QList<KWayland::Server::OutputDeviceInterface*> m_outputs;
     KWayland::Server::OutputManagementInterface *m_outputManagement;
     KWayland::Server::DpmsManagerInterface *m_dpmsManager;
+    bool m_suspendChanges;
+    KWayland::Server::OutputConfigurationInterface *m_waiting;
 };
 
 } // namespace
diff --git a/tests/kwayland/waylandtestserver.cpp b/tests/kwayland/waylandtestserver.cpp
--- a/tests/kwayland/waylandtestserver.cpp
+++ b/tests/kwayland/waylandtestserver.cpp
@@ -19,7 +19,6 @@
 #include "waylandtestserver.h"
 
 #include "waylandconfigreader.h"
-#include <QDebug>
 
 #include <QJsonArray>
 #include <QJsonDocument>
@@ -41,6 +40,8 @@
     , m_display(nullptr)
     , m_outputManagement(nullptr)
     , m_dpmsManager(nullptr)
+    , m_suspendChanges(false)
+    , m_waiting(nullptr)
 {
 }
 
@@ -106,9 +107,23 @@
     return m_outputs;
 }
 
+void WaylandTestServer::suspendChanges(bool suspend)
+{
+    if (m_suspendChanges == suspend) {
+        return;
+    }
+    m_suspendChanges = suspend;
+    if (!suspend && m_waiting) {
+        m_waiting->setApplied();
+        m_waiting = nullptr;
+        Q_EMIT configChanged();
+    }
+}
+
 void WaylandTestServer::configurationChangeRequested(KWayland::Server::OutputConfigurationInterface* configurationInterface)
 {
     qCDebug(KSCREEN_WAYLAND_TESTSERVER) << "Server received change request, changes:" << configurationInterface->changes().count();
+    Q_EMIT configReceived();
 
     auto changes = configurationInterface->changes();
     Q_FOREACH (const auto &outputdevice, changes.keys()) {
@@ -135,6 +150,12 @@
         }
     }
 
+    if (m_suspendChanges) {
+        Q_ASSERT(!m_waiting);
+        m_waiting = configurationInterface;
+        return;
+    }
+
     configurationInterface->setApplied();
     //showOutputs();
     Q_EMIT configChanged();