diff --git a/shell/dbus/org.kde.PlasmaShell.xml b/shell/dbus/org.kde.PlasmaShell.xml
--- a/shell/dbus/org.kde.PlasmaShell.xml
+++ b/shell/dbus/org.kde.PlasmaShell.xml
@@ -29,5 +29,6 @@
     </method>
     <method name="activateLauncherMenu">
     </method>
+    <property name="isStartupCompleted" type="b" access="read"/>
   </interface>
 </node>
diff --git a/shell/shellcorona.h b/shell/shellcorona.h
--- a/shell/shellcorona.h
+++ b/shell/shellcorona.h
@@ -70,6 +70,8 @@
     Q_OBJECT
     Q_PROPERTY(QString shell READ shell WRITE setShell)
     Q_PROPERTY(int numScreens READ numScreens)
+    // moc cannot cope with a NOTIFY signal that is in an inherited and not this particular class
+    Q_PROPERTY(bool startupCompleted READ isStartupCompleted NOTIFY startupCompletedChanged)
     Q_CLASSINFO("D-Bus Interface", "org.kde.PlasmaShell")
 
 public:
@@ -113,6 +115,8 @@
 
     QString defaultContainmentPlugin() const;
 
+signals:
+    void startupCompletedChanged();
 
 protected:
     bool eventFilter(QObject *watched, QEvent *event) override;
diff --git a/shell/shellcorona.cpp b/shell/shellcorona.cpp
--- a/shell/shellcorona.cpp
+++ b/shell/shellcorona.cpp
@@ -141,6 +141,9 @@
                 ksplashProgressMessage.setArguments(QList<QVariant>() << QStringLiteral("desktop"));
                 QDBusConnection::sessionBus().asyncCall(ksplashProgressMessage);
                 //TODO: remove
+
+                // moc cannot cope with a NOTIFY signal that is in an inherited class, forwarding to one in this class
+                emit startupCompletedChanged();
             });
 
     // Look for theme config in plasmarc, if it isn't configured, take the theme from the