diff --git a/autotests/testscreenconfig.cpp b/autotests/testscreenconfig.cpp
--- a/autotests/testscreenconfig.cpp
+++ b/autotests/testscreenconfig.cpp
@@ -38,14 +38,15 @@
 
 private Q_SLOTS:
     void initTestCase();
+    void cleanupTestCase();
+
     void singleOutput();
     void singleOutputWithoutPreferred();
     void multiOutput();
     void clonesOutput();
     void configCanBeApplied();
     void supportedFeatures();
     void testInvalidMode();
-    void cleanupTestCase();
     void testOutputPositionNormalization();
 };
 
@@ -97,6 +98,7 @@
     QCOMPARE(screen->currentSize(), QSize(1280, 800));
 
     QCOMPARE(config->outputs().count(), 1);
+    QCOMPARE(config->connectedOutputsHash(), QStringLiteral("6238ed9400a789a4925099b532ec8c61"));
 
     const OutputPtr output = config->outputs().take(1);
     QVERIFY(!output.isNull());
@@ -113,6 +115,7 @@
     QCOMPARE(output->isConnected(), true);
     QCOMPARE(output->isEnabled(), true);
     QCOMPARE(output->isPrimary(), true);
+    QCOMPARE(output->hash(), QStringLiteral("9384061b2b87ad193f841e07d60e9e1a"));
     //QCOMPARE(output->isEmbedded(), true);
     QVERIFY2(output->clones().isEmpty(), "In singleOutput is impossible to have clones");
 
@@ -138,15 +141,16 @@
 {
     qputenv("KSCREEN_BACKEND_ARGS", "TEST_DATA=" TEST_DATA "multipleoutput.json");
 
-    const ConfigPtr config = getConfig();
+    ConfigPtr config = getConfig();
     QVERIFY(!config.isNull());
     const ScreenPtr screen = config->screen();
     QVERIFY(!screen.isNull());
 
     QCOMPARE(screen->minSize(), QSize(320, 200));
     QCOMPARE(screen->maxSize(), QSize(8192, 8192));
     QCOMPARE(screen->currentSize(), QSize(3200, 1880));
 
+    QCOMPARE(config->connectedOutputsHash(), QStringLiteral("a852c6ad86a3150d6a49219024deda60"));
     QCOMPARE(config->outputs().count(), 2);
 
     const OutputPtr output = config->outputs().take(2);
@@ -164,12 +168,36 @@
     QCOMPARE(output->isConnected(), true);
     QCOMPARE(output->isEnabled(), true);
     QCOMPARE(output->isPrimary(), false);
+    QCOMPARE(output->hash(), QStringLiteral("be55eeb5fcc1e775f321c1ae3aa02ef0"));
     QVERIFY2(output->clones().isEmpty(), "This simulates extended output, no clones");
 
     const ModePtr mode = output->currentMode();
     QVERIFY(!mode.isNull());
     QCOMPARE(mode->size(), QSize(1920, 1080));
     QCOMPARE(mode->refreshRate(), (float)60.0);
+
+    QSignalSpy removeSpy(config.data(), &Config::outputRemoved);
+    QVERIFY(removeSpy.isValid());
+    QSignalSpy connectedOutputsHashSpy(config.data(), &Config::connectedOutputsHashChanged);
+    QVERIFY(connectedOutputsHashSpy.isValid());
+
+    config->removeOutput(output->id());
+
+    QCOMPARE(config->outputs().count(), 1);
+    QCOMPARE(removeSpy.count(), 1);
+    QCOMPARE(connectedOutputsHashSpy.count(), 1);
+    QCOMPARE(config->outputs().take(1)->hash(), QStringLiteral("9384061b2b87ad193f841e07d60e9e1a"));
+    QCOMPARE(config->connectedOutputsHash(), QStringLiteral("6238ed9400a789a4925099b532ec8c61"));
+
+    QSignalSpy addSpy(config.data(), &Config::outputAdded);
+    QVERIFY(addSpy.isValid());
+
+    config->addOutput(output);
+
+    QCOMPARE(config->outputs().count(), 2);
+    QCOMPARE(addSpy.count(), 1);
+    QCOMPARE(connectedOutputsHashSpy.count(), 2);
+    QCOMPARE(config->connectedOutputsHash(), QStringLiteral("a852c6ad86a3150d6a49219024deda60"));
 }
 
 void testScreenConfig::clonesOutput()
diff --git a/src/config.h b/src/config.h
--- a/src/config.h
+++ b/src/config.h
@@ -168,6 +168,7 @@
       void outputAdded(const KScreen::OutputPtr &output);
       void outputRemoved(int outputId);
       void primaryOutputChanged(const KScreen::OutputPtr &output);
+      void connectedOutputsHashChanged();
 
   private:
     Q_DISABLE_COPY(Config)
diff --git a/src/config.cpp b/src/config.cpp
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -81,15 +81,35 @@
         output->disconnect(q);
 
         Q_EMIT q->outputRemoved(outputId);
+        recalculateConnectedOutputsHash();
 
         return iter;
     }
 
+    void recalculateConnectedOutputsHash()
+    {
+        QStringList hashedOutputs;
+        const auto outputs = q->connectedOutputs();
+        for (const OutputPtr &output : outputs) {
+            hashedOutputs << output->hash();
+        }
+        std::sort(hashedOutputs.begin(), hashedOutputs.end());
+        const auto byteHash = QCryptographicHash::hash(hashedOutputs.join(QString()).toLatin1(),
+                                                   QCryptographicHash::Md5);
+        const auto hash = QString::fromLatin1(byteHash.toHex());
+        if (hash == connectedOutputsHash) {
+            return;
+        }
+        connectedOutputsHash = hash;
+        Q_EMIT q->connectedOutputsHashChanged();
+    }
+
     bool valid;
     ScreenPtr screen;
     OutputPtr primaryOutput;
     OutputList outputs;
     Features supportedFeatures;
+    QString connectedOutputsHash;
 
 private:
     Config *q;
@@ -223,16 +243,7 @@
 
 QString Config::connectedOutputsHash() const
 {
-    QStringList hashedOutputs;
-
-    const auto outputs = connectedOutputs();
-    for (const OutputPtr &output : outputs) {
-        hashedOutputs << output->hash();
-    }
-    std::sort(hashedOutputs.begin(), hashedOutputs.end());
-    const auto hash = QCryptographicHash::hash(hashedOutputs.join(QString()).toLatin1(),
-                                               QCryptographicHash::Md5);
-    return QString::fromLatin1(hash.toHex());
+    return d->connectedOutputsHash;
 }
 
 ScreenPtr Config::screen() const
@@ -317,8 +328,15 @@
     d->outputs.insert(output->id(), output);
     connect(output.data(), &KScreen::Output::isPrimaryChanged,
             d, &KScreen::Config::Private::onPrimaryOutputChanged);
+    connect(output.data(), &KScreen::Output::isConnectedChanged,
+            d, &KScreen::Config::Private::recalculateConnectedOutputsHash);
+    if (!output->edid()) {
+        connect(output.data(), &KScreen::Output::edidSet,
+                d, &KScreen::Config::Private::recalculateConnectedOutputsHash);
+    }
 
     Q_EMIT outputAdded(output);
+    d->recalculateConnectedOutputsHash();
 
     if (output->isPrimary()) {
         setPrimaryOutput(output);
diff --git a/src/output.h b/src/output.h
--- a/src/output.h
+++ b/src/output.h
@@ -251,6 +251,7 @@
         void clonesChanged();
         void scaleChanged();
         void followPreferredModeChanged(bool followPreferredMode);
+        void edidSet();
 
         /** The mode list changed.
          *
diff --git a/src/output.cpp b/src/output.cpp
--- a/src/output.cpp
+++ b/src/output.cpp
@@ -477,6 +477,7 @@
 {
     Q_ASSERT(d->edid.isNull());
     d->edid.reset(new Edid(rawData));
+    Q_EMIT edidSet();
 }
 
 Edid *Output::edid() const
@@ -593,6 +594,7 @@
     // Non-notifyable changes
     if (other->d->edid) {
         d->edid.reset(other->d->edid->clone());
+        changes << &Output::edidSet;
     }
 
     blockSignals(keepBlocked);