diff --git a/kcm/src/widget.cpp b/kcm/src/widget.cpp
--- a/kcm/src/widget.cpp
+++ b/kcm/src/widget.cpp
@@ -87,7 +87,7 @@
     mPrimaryCombo = new QComboBox(this);
     mPrimaryCombo->setSizeAdjustPolicy(QComboBox::AdjustToContents);
     mPrimaryCombo->addItem(i18n("No primary screen"));
-    connect(mPrimaryCombo, static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+    connect(mPrimaryCombo, static_cast<void(QComboBox::*)(int)>(&QComboBox::activated),
             this, &Widget::slotPrimaryChanged);
 
     hbox->addWidget(new QLabel(i18n("Primary display:")));
@@ -231,7 +231,6 @@
 
 void Widget::initPrimaryCombo()
 {
-    mPrimaryCombo->blockSignals(true);
     mPrimaryCombo->clear();
     mPrimaryCombo->addItem(i18n("No primary output"));
 
@@ -245,7 +244,6 @@
             mPrimaryCombo->setCurrentIndex(mPrimaryCombo->count() - 1);
         }
     }
-    mPrimaryCombo->blockSignals(false);
 }
 
 
@@ -262,18 +260,14 @@
         mPrimaryCombo->setCurrentIndex(0);
         return;
     }
-    mPrimaryCombo->blockSignals(true);
     mPrimaryCombo->setCurrentIndex(index);
-    mPrimaryCombo->blockSignals(false);
 }
 
 void Widget::slotPrimaryChanged(int index)
 {
     const int id = mPrimaryCombo->itemData(index).toInt();
     for (KScreen::OutputPtr &output : mConfig->outputs()) {
-        output->blockSignals(true);
         output->setPrimary(output->id() == id);
-        output->blockSignals(false);
     }
 
     Q_EMIT changed();