diff --git a/src/platformtheme/qdbusmenubar.cpp b/src/platformtheme/qdbusmenubar.cpp
--- a/src/platformtheme/qdbusmenubar.cpp
+++ b/src/platformtheme/qdbusmenubar.cpp
@@ -62,6 +62,12 @@
             m_menuAdaptor, &QDBusMenuAdaptor::ItemsPropertiesUpdated);
     connect(m_menu, &QDBusPlatformMenu::updated,
             m_menuAdaptor, &QDBusMenuAdaptor::LayoutUpdated);
+
+    // This signal is new in Qt 5.8 but distros might have backported it, hence a runtime look-up
+    if (m_menu->metaObject()->indexOfSignal("popupRequested(int,uint)") != -1) {
+        connect(m_menu, SIGNAL(popupRequested(int,uint)), m_menuAdaptor, SIGNAL(ItemActivationRequested(int,uint)));
+    }
+
     /*Qt 5.7.0 contains a nasty bug
     *
     * QMenuBar::setVisible() only checks isNativeMenuBar on OS X