diff --git a/src/plasmaquick/dialog.cpp b/src/plasmaquick/dialog.cpp
index e720c4cf9..e9ba73e44 100644
--- a/src/plasmaquick/dialog.cpp
+++ b/src/plasmaquick/dialog.cpp
@@ -565,7 +565,7 @@ void DialogPrivate::updateInputShape()
         return;
     }
 
-    if (QGuiApplication::platformName() == QStringLiteral("xcb")) {
+    if (KWindowSystem::isPlatformX11()) {
         xcb_connection_t *c = QX11Info::connection();
         static bool s_shapeExtensionChecked = false;
         static bool s_shapeAvailable = false;