diff --git a/kcm/src/resolutionslider.h b/kcm/src/resolutionslider.h
--- a/kcm/src/resolutionslider.h
+++ b/kcm/src/resolutionslider.h
@@ -49,6 +49,8 @@
     void slotOutputModeChanged();
 
   private:
+    void init();
+
     KScreen::OutputPtr mOutput;
 
     QList<QSize> mModes;
diff --git a/kcm/src/resolutionslider.cpp b/kcm/src/resolutionslider.cpp
--- a/kcm/src/resolutionslider.cpp
+++ b/kcm/src/resolutionslider.cpp
@@ -47,16 +47,40 @@
 {
     connect(output.data(), &KScreen::Output::currentModeIdChanged,
             this, &ResolutionSlider::slotOutputModeChanged);
+    connect(output.data(), &KScreen::Output::modesChanged,
+            this, &ResolutionSlider::init);
 
-    Q_FOREACH (const KScreen::ModePtr &mode, output->modes()) {
+    init();
+}
+
+ResolutionSlider::~ResolutionSlider()
+{
+}
+
+void ResolutionSlider::init()
+{
+    mModes.clear();
+    Q_FOREACH (const KScreen::ModePtr &mode, mOutput->modes()) {
         if (mModes.contains(mode->size())) {
             continue;
         }
 
         mModes << mode->size();
     }
     qSort(mModes.begin(), mModes.end(), sizeLessThan);
 
+    delete layout();
+    delete mSmallestLabel;
+    mSmallestLabel = nullptr;
+    delete mBiggestLabel;
+    mBiggestLabel = nullptr;
+    delete mCurrentLabel;
+    mCurrentLabel = nullptr;
+    delete mSlider;
+    mSlider = nullptr;
+    delete mComboBox;
+    mComboBox = nullptr;
+
     QGridLayout *layout = new QGridLayout(this);
 
     if (mModes.count() > 15) {
@@ -66,14 +90,16 @@
         mComboBox->setEditable(false);
         Q_FOREACH (const QSize &size, mModes) {
             mComboBox->addItem(Utils::sizeToString(size));
-            if ((output->currentMode() && (output->currentMode()->size() == size))
-                || (output->preferredMode() && (output->preferredMode()->size() == size))) {
+            if ((mOutput->currentMode() && (mOutput->currentMode()->size() == size))
+                || (mOutput->preferredMode() && (mOutput->preferredMode()->size() == size))) {
                     mComboBox->setCurrentIndex(mComboBox->count() - 1);
             }
         }
         layout->addWidget(mComboBox, 0, 0, 1, 1);
         connect(mComboBox, static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
-                this, &ResolutionSlider::slotValueChanged);
+                this, &ResolutionSlider::slotValueChanged, Qt::UniqueConnection);
+
+        Q_EMIT resolutionChanged(mModes.at(mComboBox->currentIndex()));
     } else {
         mCurrentLabel = new QLabel(this);
         mCurrentLabel->setAlignment(Qt::AlignCenter);
@@ -92,10 +118,10 @@
             mSlider->setMinimum(0);
             mSlider->setMaximum(mModes.size() - 1);
             mSlider->setSingleStep(1);
-            if (output->currentMode()) {
-                mSlider->setValue(mModes.indexOf(output->currentMode()->size()));
-            } else if (output->preferredMode()) {
-                mSlider->setValue(mModes.indexOf(output->preferredMode()->size()));
+            if (mOutput->currentMode()) {
+                mSlider->setValue(mModes.indexOf(mOutput->currentMode()->size()));
+            } else if (mOutput->preferredMode()) {
+                mSlider->setValue(mModes.indexOf(mOutput->preferredMode()->size()));
             } else {
                 mSlider->setValue(mSlider->maximum());
             }
@@ -110,15 +136,13 @@
             mBiggestLabel->setText(Utils::sizeToString(mModes.last()));
             layout->addWidget(mBiggestLabel, 0, 2);
 
-            mCurrentLabel->setText(Utils::sizeToString(mModes.at(mSlider->value())));
+            const auto size = mModes.at(mSlider->value());
+            mCurrentLabel->setText(Utils::sizeToString(size));
+            Q_EMIT resolutionChanged(size);
         }
     }
 }
 
-ResolutionSlider::~ResolutionSlider()
-{
-}
-
 QSize ResolutionSlider::currentResolution() const
 {
     if (mModes.isEmpty()) {