diff --git a/autotests/integration/globalshortcuts_test.cpp b/autotests/integration/globalshortcuts_test.cpp
--- a/autotests/integration/globalshortcuts_test.cpp
+++ b/autotests/integration/globalshortcuts_test.cpp
@@ -55,6 +55,7 @@
     void testRepeatedTrigger();
     void testUserActionsMenu();
     void testMetaShiftW();
+    void testComponseKey();
     void testX11ClientShortcut();
     void testWaylandClientShortcut();
     void testSetupWindowShortcut();
@@ -203,6 +204,25 @@
     kwinApp()->platform()->keyboardKeyReleased(KEY_LEFTMETA, timestamp++);
 }
 
+void GlobalShortcutsTest::testComponseKey()
+{
+    // BUG 390110
+    QScopedPointer<QAction> action(new QAction(nullptr));
+    action->setProperty("componentName", QStringLiteral(KWIN_NAME));
+    action->setObjectName(QStringLiteral("globalshortcuts-accent"));
+    QSignalSpy triggeredSpy(action.data(), &QAction::triggered);
+    QVERIFY(triggeredSpy.isValid());
+    KGlobalAccel::self()->setShortcut(action.data(), QList<QKeySequence>{Qt::UNICODE_ACCEL}, KGlobalAccel::NoAutoloading);
+    input()->registerShortcut(Qt::UNICODE_ACCEL, action.data());
+
+    // press & release `
+    quint32 timestamp = 0;
+    kwinApp()->platform()->keyboardKeyPressed(KEY_RESERVED, timestamp++);
+    kwinApp()->platform()->keyboardKeyReleased(KEY_RESERVED, timestamp++);
+
+    QTRY_COMPARE(triggeredSpy.count(), 0);
+}
+
 struct XcbConnectionDeleter
 {
     static inline void cleanup(xcb_connection_t *pointer)
diff --git a/globalshortcuts.cpp b/globalshortcuts.cpp
--- a/globalshortcuts.cpp
+++ b/globalshortcuts.cpp
@@ -245,6 +245,9 @@
 bool GlobalShortcutsManager::processKey(Qt::KeyboardModifiers mods, int keyQt)
 {
     if (m_kglobalAccelInterface) {
+        if (!keyQt && !mods) {
+            return false;
+        }
         auto check = [this] (Qt::KeyboardModifiers mods, int keyQt) {
             bool retVal = false;
             QMetaObject::invokeMethod(m_kglobalAccelInterface,