diff --git a/kded/daemon.cpp b/kded/daemon.cpp
--- a/kded/daemon.cpp
+++ b/kded/daemon.cpp
@@ -252,13 +252,17 @@
     logConfig(m_monitoredConfig);
 
     // Modes may have changed, fix-up current mode id
+    bool changed = false;
     Q_FOREACH(const KScreen::OutputPtr &output, m_monitoredConfig->outputs()) {
         if (output->isConnected() && output->isEnabled() && output->currentMode().isNull()) {
             qCDebug(KSCREEN_KDED) << "Current mode" << output->currentModeId() << "invalid, setting preferred mode" << output->preferredModeId();
             output->setCurrentModeId(output->preferredModeId());
-            doApplyConfig(m_monitoredConfig);
+            changed = true;
         }
     }
+    if (changed) {
+        doApplyConfig(m_monitoredConfig);
+    }
 
     // Reset timer, delay the writeback
     if (!m_saveTimer) {