diff --git a/src/platformtheme/kdeplatformfiledialoghelper.cpp b/src/platformtheme/kdeplatformfiledialoghelper.cpp
--- a/src/platformtheme/kdeplatformfiledialoghelper.cpp
+++ b/src/platformtheme/kdeplatformfiledialoghelper.cpp
@@ -330,11 +330,11 @@
 
 bool KDEPlatformFileDialogHelper::show(Qt::WindowFlags windowFlags, Qt::WindowModality windowModality, QWindow *parent)
 {
-    Q_UNUSED(parent)
     initializeDialog();
     m_dialog->setWindowFlags(windowFlags);
     m_dialog->setWindowModality(windowModality);
     restoreSize();
+    m_dialog->windowHandle()->setTransientParent(parent);
     // Use a delayed show here to delay show() after the internal Qt invisible QDialog.
     // The delayed call shouldn't matter, because for other "real" native QPlatformDialog
     // implementation like Mac and Windows, the native dialog is not necessarily